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	England and Wales High Court (Queen's Bench Division) Decisions
You are here: BAILII >> Databases >> England and Wales High Court (Queen's Bench Division) Decisions >> Parkin & Ors v Alba Proteins Ltd & Ors [2013] EWHC 2036 (QB) (31 July 2013) URL: http://www.bailii.org/ew/cases/EWHC/QB/2013/2036.html Cite as: [2013] EWHC 2036 (QB)

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IN THE HIGH COURT OF JUSTICE
QUEEN'S BENCH DIVISION
CARLISLE DISTRICT REGISTRY
WILDRIGGS RENDERING SITE GROUP LITIGATION

		31/07/2013

Mr Justice Holroyde:

1. On 17^th and 18^th July 2013 I heard submissions on issues relating to limitation and allied matters. I reserved my judgment, indicating that I would hand it down in writing as soon as possible. This I now do.
2. The Claimants ("Cs") live in the area of Penrith, Cumbria. They claim an injunction and damages for what is alleged to be a continuing nuisance by odour caused by rendering operations at premises in that area known as the Wildriggs site ("the site"). The operations at the site are of a kind which requires an environmental permit. In this case the regulator is the local authority, Eden District Council ("EDC"), and the evidence in the case includes various documents relating to the granting and varying of permits.
3. It is now common ground that the operators of the site at times material to this action have been as follows: from a date prior to 1^st January 2005 until 24^th December 2006, Alba Proteins Limited ("D1"); from 25^th December 2006 until 30^th April 2011, Alba Proteins Penrith Limited ("D2"); and from 1^st May 2011 to the present, Omega Proteins Limited ("D3"). All three defendants are members of the same group of companies, of which the parent company is Leo Group Limited ("Leo"). For convenience I will refer to them throughout as D1, D2 and D3, even though (as will become apparent) the proceedings were originally commenced against D2 alone.
4. A paginated bundle was prepared for the purposes of this hearing which contained some but by no means all of the correspondence between the parties. Where I refer in this judgment to page numbers, the reference is to that bundle. I bear in mind the point made on behalf of the defendants that I must be careful not to assume that there is no other relevant correspondence. On the other hand, I also bear in mind that it was open to either party to add further correspondence if it was thought important for me to see it.
5. Proceedings were commenced on 23^rd December 2010, when a claim was issued against D2 alone. There were hearings before Irwin J, in the course of which a Group Litigation Order ("GLO") was made. Subsequently, I became the judge managing the proceedings.
6. On 26^th October 2012 I made an order inter alia in the following terms:

"1. The Claimants have permission to add [D1] and [D3] as First and Third Defendants to these proceedings notwithstanding the provisions of s35(1)(b) of the Limitation Act 1980 and without prejudice to any point which they may choose to take as to limitation. …

10. Any issue which may arise as to limitation should be referred to the management Court by way of a Part 23 application notice. …".

7. Directions were given as to the amendment of pleadings and as to the time for any application in relation to any issue of limitation. In Amended Group Particulars of Claim dated 31^st October 2012, Cs pleaded the successive operation of the site by the three defendants and maintained their claim for damages for nuisance suffered since 1^st January 2005. In an Amended Defence dated 14^th November 2012 D1 pleaded that any claims against it which are said to have accrued before 14^th November 2006 are statute-barred. That date is pleaded because D1 accepts that it is deemed to have been served with the Amended Claim Form on 14^th November 2012.
8. Thus in a nutshell, Cs seek compensation from D1 for nuisance suffered by Cs from 1^st January 2005 until D1 ceased to operate the site on 24^th December 2006, whilst D1 asserts that any claim accruing against it before 14^th November 2006 is statute-barred.
9. On 19^th December 2012 and 25^th June 2013 Cs issued the two Part 23 application notices on which I have to rule. By these applications, Cs seek a declaration that their claims which accrued against D1 before 14^th November 2006 are not time-barred, and an order that for the purposes of these proceedings D2 is prevented from denying that it was the operator of the site for a period six years prior to the issue of the Claim Form and up to 1^st May 2011, and unable to claim that the claims against it are statute-barred.
10. Each of the application notices is supported by witness statements of Miss Elin Gwen Evans ("Miss Evans"), Cs' solicitor, these being dated 20^th December 2012 (p4) and 24^th June 2013 (p309) respectively. The essence of her evidence is the assertion at paragraph 11 of her first statement (p6) that Cs "have been positively led to believe from an early stage that the correct defendant was solely" D2.
11. All three defendants are now represented by Clarke Willmott LLP. The evidence on which they rely is contained in a statement dated 28^th February 2013 (p235) by Mr Ian Smith ("Mr Smith"), the in-house solicitor in Leo's legal department.
12. The course of proceedings will become apparent in more detail as I review the chronology of relevant events, to which I now turn.
13. On 3^rd September 2009, Cs' solicitors wrote to D2 (p49) indicating that they acted for a number of local residents who wished to claim an injunction (if appropriate) and damages "against the operator of the Alba Proteins factory" in connection with the odour problem emanating from that factory. The letter made clear that the allegation of nuisance went back for a number of years, and specifically referred to the limitation period of 6 years. The letter said -

"We believe that the appropriate Defendant is [D2]. Please confirm that this is correct and confirm an address for service".

14. Thus from the outset it was made clear to D2 that Cs claimed damages for a nuisance which was alleged to have begun some years before D2 became responsible for the site.
15. There was no reply to that letter. As will become apparent, it is a regrettable feature of the evidence that letters sent by Cs' solicitors have frequently received no reply.
16. On 9^th October 2009 Cs' solicitors wrote in broadly similar terms to D1 (p51). They again asked for confirmation that they were writing to the correct defendant. Again they received no reply.
17. On 11^th November 2009, Cs' solicitors again wrote to D1 (p316), once again in broadly similar terms. They referred to their earlier letter, and asked whether D1 had insurance cover against the likely claims. Again, no one reading this letter could have been in any doubt that the prospective claimants alleged a continuing nuisance by unpleasant odours emanating from the operations carried on at the site since the mid-1990s, and wished to claim damages for such period as the Limitation Act would permit. D1 did not reply to the effect that it had no responsibility for the operation of the site after 23^rd December 2006. Indeed, it did not reply at all.
18. On 4^th May 2010 Cs' solicitors wrote to D1 (p53). They referred to previous correspondence which had not been answered. They indicated that when insurance cover had been obtained to support a conditional fee agreement, they would seek a GLO. They urged D1 to instruct solicitors.
19. On 15^th June 2010 Cs' solicitors wrote a letter to Leo as the parent company of D2. A copy of that letter was added to the bundle at my instigation during the hearing, but does not have a page number. They pointed out that all correspondence sent to D2 had thus far gone unanswered, and indicated that they were now in a position to commence proceedings. D2 replied (p55), saying that Cs' allegations had not been substantiated by any evidence and that it did not accept "any liability for unsubstantiated allegations". The letter was silent as to the date when D2 began to operate the site.
20. On 24^th June 2010 Cs made a company search in respect of D2, which showed (p269) that D2 was incorporated on 4^th April 2006.
21. On 2^nd September 2010 Cs issued an application against D2 for pre-action disclosure (p71). That application was supported by a statement from Miss Evans dated 15^th October 2010 (p73). Paragraph 9 gave details of the number of odour complaints received by EDC in the 10 years between 1997 and 2007. These showed that in the last six years, the greatest number of complaints had been received in 2005 and 2006. Paragraph 11 indicated that Cs were likely to claim "compensation for past nuisance limited to the period of 6 years prior to the date of issue" and possibly also an injunction. Paragraph 19 indicated that the purpose of the application was to obtain material, not so far made available by D2, so that Cs could be properly advised as to the merits of the claim. In paragraph 25 Miss Evans commented that the case was unique in her experience "since in most cases a defendant's legal representatives are only too keen to explain why their clients are not responsible for a nuisance". In paragraph 31 she said –

"There is now an element of urgency about the application since the Claimants are anxious that something should be done about the nuisance but also because the limitation period in respect of one particularly bad year, namely 2005, is approaching".

22. That statement made it entirely clear that a claim for damages for nuisance allegedly caused in 2005, and thereafter, was an important part of Cs' case. D2 knew that it did not operate the site in 2005, or for most of 2006. D2 knew who was responsible for the operation of the site in those years.
23. On 20^th September 2010 Dyne Solicitors wrote (p57) to say they had just been instructed by D2 "in relation to the matters raised by your letter of 2^nd September and the previous correspondence relating to alleged odour nuisance". That was, of course, a reference to the correspondence summarised above, in which Cs had alleged a continuing nuisance over many years. Dyne Solicitors went on to say that they would respond more fully in due course.
24. Dyne Solicitors did so on 19^th October 2010 (p58). They suggested that Cs' expert witness had relied on information from EDC which was out of date, and had misunderstood important matters. They said:

"Since the grant of the permit the site has submitted variations to EDC that aim to upgrade and improve the site's performance. It would appear that your expert has not attended the site since 1994. In that time the site has changed considerably and we feel that it will be beneficial for him to re-visit the site and understand the processes that are now in operation"

25. It is to be noted that in referring to changes to the site in the period since 1994, D2's solicitors did not mention the important change in the site operators. They said nothing to suggest that they were acting for a prospective defendant which could not possibly be liable for any nuisance which occurred before late 2006. On an objective reading, the letter as a whole appeared to be written on the basis that D2 had been the sole operator throughout the period of the proposed claim.
26. On 26^th October 2010 (p326) Cs' solicitors wrote to D2's solicitors seeking – unsuccessfully, as it transpired - a "limitation amnesty agreement". The letter began:

"As you are aware our clients allege a historical nuisance in this case. We recognise that any case pursued will be limited to six years prior to the date of issue in the absence of the parties' agreement."

27. D2 accepts that thus far, nothing had been said to indicate or even to suggest that D2 had only become responsible for the operation of the site at a time within the last 6 years. Nor was anything said to that effect in the course of a site visit by Cs' expert witness in November 2010. D2's case is that it was under no obligation to mention that fact, or to identify D1 as the previous operator, either in correspondence or in the course of the site visit.
28. On 8^th December 2010 D2's solicitors wrote (p61) complaining that Cs' solicitors had failed to provide any particulars of the dates and times of alleged odour nuisance. The letter referred throughout either to "our client's Penrith site" or to "the site". Reference was made to various permits which had been issued, and to the fact that no enforcement action had ever been necessary by EDC against D2. The letter concluded by saying -

"… in the absence of adequate particulars of claim we are unwilling to indulge you in what appears to be no more than a fishing exercise".

29. The tenor of this letter as a whole was that Cs' solicitors had not undertaken even a modicum of investigation with the regulators, and were wholly lacking in an understanding of how the site was operated and regulated. The letter nonetheless said nothing at all about the date on which D2 had become responsible for the operation of the site, nor did it say that C was engaged in a fishing exercise in relation to a period when D2 was not so responsible. It was a detailed letter, in which Cs' solicitors were criticised in a number of respects; but it is to be noted that nothing was said to the effect that Cs' solicitors had failed even to identify the appropriate defendant for part of their threatened proceedings.
30. On 23^rd December 2010, Cs issued against D2 (but did not serve) a claim form (p66) claiming "damages and/or an injunction, interest and costs in nuisance from the defendant".
31. On 25^th January 2011 Dyne Solicitors wrote (p69) reporting that they were no longer instructed by D2, and asking that all future correspondence be sent to D2 direct.
32. On 16^th March 2011 Cs issued against D2 an application for a GLO. They provided a draft of the order sought, in which the common or related issues of fact and law said to be raised by the individual claims were said (p334) to include –

"Whether, for the period beginning on 1^st January 2005, the Claimants' complaints of nuisance as a result of odours are complaints about emissions caused by the Defendant as a result of the operation of its Wildriggs Rendering Site …".

33. On 15^th April 2011, D2's solicitor Mr Neil Ham made a witness statement (p94) opposing the application for disclosure.
34. Cs' applications made it entirely clear that the court was being asked to make a GLO in respect of claims against D2 in respect of its operation of the site from 1^st January 2005 onwards, and to consider pre-action disclosure on a similar basis. D2 was not responsible for the site until nearly two years after that date. Yet in the course of two hearings before Irwin J, which D2 contested, and in which it was made clear that Cs did not wish to commence proceedings if in reality their proposed claim was without merit, nothing was ever brought to the attention of the court as to when D2 became responsible for the site. On the contrary: one of the grounds on which D2 challenged the application for disclosure was that it was far too wide, and a skeleton argument signed by leading and junior counsel p347 said -

"The Defendant has no detailed allegations as to dates of alleged incidents in 2005. To provide details of its operations in 2005 without them would not be to further the overriding objective of dealing with the case justly/ensuring the parties are on an equal footing".

35. On 18^th April 2011 the GLO was made.
36. On 29^th June 2011 Mr David Green, an environmental consultant acting for D2, made a statement opposing further voluntary disclosure. It should be noted that D3 were by this time responsible for the operation of the site. Neither that fact, nor the earlier role of D1, was mentioned by Mr Green.
37. On that same date Irwin J, in an endeavour to assist the parties to resolve the issues between them as to disclosure, gave an indication that any voluntary disclosure need not relate to a period starting any earlier than 1^st January 2009. Mr Green referred to that in a second witness statement dated 13^th July 2011, saying (p158) –

"Before this, Cs had been pressing for disclosure from [D2] back to at least 1 January 2005. From my knowledge of the operations of [D2], this potentially involved providing a vast amount of data which is not readily retrievable from computer or otherwise and the volume of paperwork involved could, according to my calculations, have been in excess of one million documents…"

38. It is to be noted that Mr Green did not say that in any event, data from the years 2005 and 2006 did not relate to D2's operation of the site.
39. On 30^th April 2012 Cs served Group Particulars of Claim against D2. Paragraph 2 alleged that D2 operates the site. Paragraph 4 states that the precise dates from which D2 commenced processing animal by-products are unknown to Cs. Paragraph 14 alleges a continuing nuisance since a date prior to 1^st January 2005 but indicates that the "claim is limited to events after 1^st January 2005 by reason of the Limitation Act".
40. On 10^th July 2012 D2 served its Generic Defence. By paragraph 2, D2 admitted "that it operated, but no longer operates" the site. Paragraph 4 went on to say:

"The Site was operated by [D2] between about the end of 2007 and mid-2011. The Site is now operated by [D3]"

41. Mr Wignall understandably describes that pleading as very coy. No explanation has been given by D2 as to why D3 was named but D1 was not. In any event, its assertion that D2 operated the site from "about the end of 2007" was wrong, because it has very belatedly transpired that in fact D2 did so from late December 2006. That error was repeated in subsequent documents, and was not corrected until the final paragraph of Mr Johns' skeleton argument in relation to the present applications: almost a year after the error was first promulgated. The court has received an unsatisfactory explanation for why that error was ever made, and no real explanation for why it was not corrected much sooner than it was.
42. Moreover, paragraph 7 of the Generic Defence went on to list a number of applications to vary the permit which it was said "the Defendant" – that is, D2 - had made. These included one in June 2011 and one in October 2011, both of which were made after D3 had taken over the operation. No explanation has been given for that.
43. In paragraph 30 of her first statement (p12), Miss Evans describes that Generic Defence as "a bolt out of the blue". She noted that the fact that Cs had issued proceedings against the incorrect defendant for part of the claim period "was not raised by anyone until service of the Generic Defence in July 2012".
44. Thus the first indication from D2 that it had not operated the site throughout the period of Cs' claim was given some 2 years 10 months after the first letter sent by Cs' solicitors (p49). Even then - less than 6 months before the expiration of the limitation period for any claim against D1 - D2 did not identify the company which had operated the site previously.
45. Agreement was reached between the parties as to the uncontroversial matter of amending the claim by adding D3 as a defendant. Clarke Willmott were instructed to act for D3. In the correspondence relating to that amendment, Cs' solicitors made the point that in the contested applications for disclosure, D2 had never suggested that they could not give any disclosure in relation to events after their operation of the site ended on 30^th April 2011.
46. In their letter to Clarke Willmott of 3^rd August 2012 (p172), Cs' solicitors dealt with the addition of D3 to the proceedings and then said –

"Finally, please confirm the identity of the party operating the site from 1 January 2005 to end of 2007 when your client is said to have commenced the operation of the site. Please also confirm whether or not it is necessary to include this party as a Defendant in these proceedings or whether any transfer between the previous operator of the site and your client provided for the transfer of liabilities".

47. Continuing what had become an established pattern, Clarke Willmott did not reply to that paragraph. They were pressed to do so in a series of further letters, to all of which they likewise failed to reply. No explanation has been given for that failure.
48. Cs' solicitors then wrote to Clarke Willmott on 17^th September 2012 (p182), saying –

"We believe that the site may have been operated by [D1]. This company is part of the Leo Group as with the other parties (proposed or current) in this litigation. We note that Mr Singh is the company secretary for all three companies. Please confirm the position".

49. On the same date Cs' solicitors wrote (p183) to D1, asking for their consent to being added as a defendant. The letter said –

"We believe that [D1] will be fully aware of this claim given that the company secretary Mr Manjit Singh holds the equivalent position at both [D3] and [D2]. It is his signature verifying the truth on the enclosed Generic Defence. Furthermore, copies of the pre-action correspondence in relation to this matter were copied to Leo Group being the parent company of all three companies listed".

50. D2 finally responded, through their solicitors Clarke Willmott, on 21^st September 2012 (p187). It is necessary to quote almost the whole of this letter:

"We are instructed by [D2] that the company which was operating Wildriggs for the period 1 January 2005 to 25 December 2007 was [D1]. Those for whom we are acting ([D2] and [D3], as we have indicated in previous correspondence) are obviously not required to provide this information about another potential defendant, and it is therefore simply supplied as such, without any liability or commitment, and is only of course relevant insofar as your clients or your firm were not already aware of the identity of the party operating the site at the pertinent time. This was however already apparent in any event from documents or information in your possession and in the public domain; and this knowledge has now been mentioned in your 17 September 2012 letter to [D1]. As you are aware, we are not acting on behalf of [D1] and we do now know why you did not attempt to verify with that company much sooner its period of operation of the site".

51. It will be noted that this letter continued the error previously made as to when D2 assumed responsibility for the site.
52. On 26^th October 2012 I made the order to which I have referred at paragraph 6 above. On 31^st October 2012 Cs issued Amended Group Particulars of Claim against all three defendants. The defendants served an Amended Generic Defence on 14^th November 2012. In particular, paragraph 14 was amended to plead that any claim against D1 which accrued before 14^th November 2006 was statute-barred. That date was explained on the basis that D1 accepted that it was deemed to have been served with the Amended Claim Form on 14^th November 2012. In a reply to that Amended Generic Defence, served on 28^th November 2012, Cs joined issue with that limitation defence.
53. On 19^th December 2012 Cs issued their first application notice (p1), supported by Miss Evans' first statement. They sought a declaration that Cs' claims which accrued against D1 before 14^th November 2006 are not statute-barred. On 28^th February 2013 Mr Smith made his statement opposing the application.
54. On 25^th June 2013 Cs issued their second notice of application (p305), supported by Miss Evans' second statement. This raised for the first time the issue of estoppel.
55. I can summarise the evidence quite briefly.
56. Miss Evans' first statement (at p6) put Cs' case on the basis that they had made a mistake as to the correct defendant, and that it was necessary for that mistake to be corrected, "the real position having been concealed from them". Without limiting the way Cs' case might be presented, she invoked s35(1)(b) of the Limitation Act 1980, and CPR 19.5. Towards the end of the statement, in paragraph 50, she encapsulated her evidence in these words:

"This witness statement is intended to illustrate to the court why Cs had always believed that they had issued proceedings against the correct defendant either as a result of a mistake or because of concealment by the defendants".

57. Miss Evans was not required to attend for cross-examination and so there was no challenge to her evidence. At paragraphs 14, 17 and 18 of her first statement (p7) she referred to the correspondence received from Dyne Solicitors in late 2010. She said that in the absence of any indication to the contrary in those letters, she formed the view that she was dealing with the correct defendant. The terms in which Dyne Solicitors wrote reinforced her view. For reasons which she explained, she said at p8 –

"The net result of the letters dated 19 October and 8 December is that it was apparently accepted by Dynes Solicitors that there was one defendant, namely [D2], and only one defendant throughout the claim period".

58. Miss Evans went on to say, at paragraph 23, that at no point during the contested disclosure hearings had D2 suggested it was not the operator at the relevant time. At paragraph 25 (p9) she gave eleven specific examples of passages in correspondence. It is not necessary for me to cite all of these, but the following should be noted:

"(a) Mr Neil Ham, of Clarke Willmott LLP, solicitor for [D2] in his first witness statement dated 15 April 2011 in which he opposed the GLO and the application for disclosure stated at paragraph 7 'the defendant cannot be expected to provide swathes of detailed technical information over a period covering all of some 6 years' …

(b) In the first statement of Mr David Green dated 29 June 2011 at paragraph 15 he stated 'Confidentiality in the defendant's business is critical to it, and essential to its competitive edge. It has invested a vast amount of money into its business processes and plant, in the region of £14 million since 2002, and it is I believe a responsible company operating to a high standard within its operating permit' …

(f) On 29 June 2011 Clarke Willmott produced a response document to the Cs' request for disclosure. At paragraph 13 in response to the Cs' comment that the GLO covers the period 1 January 2005 Clarke Willmott on behalf of the defendant stated 'The January 2005 date was provided for in the GLO for statutory limitation purposes since it is approximately 6 years before the claim form was issued … voluntary disclosure is not pegged to the period from 1 January 2005 onwards. Early disclosure for all of that period would be inappropriate, oppressive and disproportionate.' This would have been a perfectly appropriate time to refer to the fact that the defendant was not correctly identified, but no such point was ever raised.

(h) Clarke Willmott prepared a detailed chronology dated 11 May 2011 purporting to provide a chronology of events relating to the plant history. This document covers the period 2002 to April 2008 and makes no reference to there being a series of defendants involved with this plant …".

59. Towards the end of her statement, at paragraph 44 (p15), Miss Evans said:

"Unfortunately, as the above chain suggests, correspondence and court documents received from both Dyne Solicitors, Clarke Willmott solicitors and indeed Mr David Green, led me to believe that we had in fact pursued the correct defendant. Had this issue been corrected and raised at the first opportunity, [D1] would not be able to take the point it now takes as to limitation".

60. In that first statement, Miss Evans put the issue principally on the basis that D2 must have been labouring under a mistake, because she found it hard to believe that there had been deliberate concealment: see paragraph 28. By the time of her second statement she had come to a different view. In paragraph 3, she said that Dyne Solicitors' letter of 8^th December 2010 (p61) led her to believe that the correct identity of the operator of the site was D2, and reiterated that she had been positively led to believe that the correct defendant was solely D2. In paragraphs 7 (p311) and 15 (p313) she said –

"(7) Whilst I was reluctant to state in my earlier statement that there was any deliberate concealment on the part of the various defendants, on re-reading the papers … I do conclude that [Cs] were misled as to the identity of the correct defendant for the early part of the claim. Moreover I consider this to have been the case right up to the time at which I saw the Group Amended Defence for the first time. …

(15) … [D2] strove very hard not to make any acknowledgement of the existence of [D1] in the context of my early requests to know who was the correct defendant during the early part of the claim. If I had know the truth as a result of my requests the [D1] would have been named on the claim form or an application to amend made as soon as I had been told. …"

61. On behalf of the defendants, Mr Ian Smith referred at paragraph 3 of his statement (p236) to the letters initially sent by Cs' solicitors to both D1 and D2, and asserted that those letters indicated that from the outset Cs had identified both those companies "as persons to be sued". He referred to a letter from Cs' solicitors indicating that before proceedings were commenced, they had made enquiries at Companies House, and to documents showing that on 24^th June 2010 Cs' solicitors carried out credit checks on both D1 and D2, as well as having inspected the local authority permit and environment agency documents. The credit check for D2 (p269) showed correctly that D2 was not incorporated until 4^th April 2006. At paragraph 6 (p237) Mr Smith said "It was certainly not apparent to me that by the proceedings as issued it was intended to sue [D1]". As to the contested application for pre-action disclosure, he pointed out (p238) that D2 as current operator of the site did have control of site records, including those maintained by D1, and said that the fact that D2 therefore dealt with the history of processes at the site "was certainly not intended to be taken as an agreement that [D2] would accept liability for any period". He denied that there had been any mistake on the defendants' side as to who operated the site at particular times, saying (p238):

"The fact is that it was only at the stage of the Generic Defence that [D2] had to address itself to formulating a defence. In doing so, it set down the fact (about which there had been no previous mistake) that it had operated the site from the end of 2007".

62. Mr Smith went on to assert that public documents showed clearly that D1 operated the site before D2 was incorporated, and that Cs did know that fact before D2 told them in September 2012 (see p239).
63. On Cs' behalf, Mr Wignall advanced three arguments, all based on a common factual foundation. First, he argued that D2 was stopped from denying that it had operated the site throughout the period since 1^st January 2005. Secondly, he invoked section 32(1)(b) of the Limitation Act 1980, on the basis that D2 had deliberately concealed a fact relevant to Cs' right of action (namely, that D1 had operated the site until 23^rd December 2006). Thirdly, he asked the court to exercise its discretion under CPR 19.5 to permit the addition of D1 as a defendant to these proceedings.
64. Before considering those submissions, and Mr Johns' response to them, and before indicating my findings as to the evidence, it is necessary to consider an initial objection raised on behalf of the defendants. Mr Johns submitted that it was inappropriate for issues such as these to be raised by a notice of application supported only by a statement of evidence. He submitted that allegations such as were being made against the defendants should be fully pleaded and should be the subject of oral evidence from witnesses on both sides. To these submissions, Mr Wignall responded that Cs had simply adopted the procedure which had been agreed between the parties, and ordered by the court, on 26^th October 2012.
65. A transcript of the proceedings on that date has very helpfully been obtained, and is included in the bundle at pp277-303. There was a draft order before the court which had been agreed between the parties. It was clear that all parties contemplated that there would be serious issues as to limitation which would have to be resolved by the court, but it was also clear that the parties were willing to postpone those issues until a later date, and in the meantime to make progress with other matters such as the amendment of the pleadings and disclosure of documents. I expressed a reservation about amending the claim to include D1 and D3 before knowing where the parties stood on the issue of limitation: see p284F. After an exchange with Mr Cahill QC, then appearing for the defendants, I said at p286B –

"… the limitation issue does need to be resolved sooner rather than later, but if the parties are content in effect to postpone that to a later stage and allow the amendment of pleadings to continue in the meantime, then that seems to me to be a satisfactorily pragmatic course to take in order to make progress".

To that, Mr Cahill responded (p286C) –

"… as far as the defendants were concerned, they were very anxious that your Lordship should be aware that this argument would be taken. And on the pragmatic basis that your Lordship has said, we are clearly going to be able to make such points on that despite the amendment".

66. Towards the end of that hearing, as I was reciting the terms in which the order would be made (including the terms of the final order which I have quoted in paragraph 6 above), there was a further exchange in which both Mr Cahill QC and Mr Wignall confirmed the understanding which I summarised in the following terms (p301H):

"… the parties were agreed that, as what I have described as a sensible pragmatic course, the amendment of the pleadings could take its own course, in effect without prejudice to all such issues as may be raised under the Limitation Act".

67. I have no doubt that it was understood and accepted by all parties on 26^th October 2012 that D1 would raise limitation issues and that no party would be prevented from advancing its submissions on those issues by reason only of the fact that the amendment to add D1 and D3 as defendants had already been made. It was with that understanding, and in contemplation of the court having in due course to resolve contentious issues of limitation, that the parties were agreed upon the procedure which was expressed in the court's order. It must have been clear to D1 and D2 that Cs were complaining that they had been led to believe they had sued the correct defendant in respect of the whole period. It must therefore have been equally clear to the defendants that the issues would or might be factual as well as legal. In those circumstances, I can see no merit in Mr Johns' objection as to the procedure which Cs have adopted. I agree with Mr Wignall that Cs have simply followed the procedure which was agreed between all parties and ordered by the court. Moreover, having regard to the detailed terms of Miss Evans' statements, the defendants have had notice of all the factual matters relied on by Cs, and have had the opportunity to require Miss Evans to attend for cross-examination if they wished. In my judgment, the defendants therefore suffer no prejudice as a result of the procedure which has been followed. The procedure agreed between the parties was and is a convenient and proportionate way of dealing with the limitation and allied issues. In the event, I heard very full submissions from both sides over more than a day.
68. I turn to the principal submissions.
69. As I have said, Cs rely on the same factual foundation for each of their three submissions. By way of overview, Mr Wignall submitted that, through no fault of their own, Cs had wrongly commenced proceedings against D2 alone, and that consistently with the overriding objective the court should by one of three possible routes enable Cs to proceed against D1 in relation to the period from 1^st January 2005 to 23^rd December 2006. He argued that Cs have throughout been trying to pursue a claim for damages for nuisance during the period starting 6 years before the issue of proceedings, and that the just result of this hearing is that Cs should be permitted to proceed against a defendant which could and should have been identified to them much sooner than it was.
70. I consider first Cs' argument based on an estoppel. This argument was raised very late in the day, and there is considerable force in Mr Johns' objection that the defendants were denied a proper opportunity for preparation of their arguments in response. His submissions in that regard are supported by ING Bank NV v Ros Roca SA [2012] 1WLR 472. In the event, however, it is not necessary for me to say more about that, because I am satisfied that Mr Johns was able to advance all submissions which he needed to advance.
71. Cs contend that D2 had conducted itself in such a way that it should not be permitted to deny its liability for any nuisance which Cs may prove during the period from 1^st January 2005 to date. To that argument there is an obvious objection: if it were correct, it would in reality breach the well-established principle that estoppel is a shield not a sword, because it would provide Cs with a cause of action against D2 (in respect of the period between 1^st January 2005 and 25^th December 2006) where none previously existed and there had been no legal relationship between the parties. Moreover, since D2 was not incorporated until 4^th April 2006, it would provide that cause of action against a company which did not even exist for most of the period concerned. I accept Mr Johns' submissions to this effect.
72. Mr Wignall sought to meet that objection by relying heavily on the decision of Webster J in The Henrik Sif [1982] 1 Lloyd's Rep 456. The plaintiffs in that case were the owners of goods shipped on a vessel owned by the second defendant but demised by them to the first defendant. The goods were delivered in an unsatisfactory condition. The bills of lading issued by the first defendant contained a clause which provided that in certain circumstances, including those which in fact obtained, the bills of lading should take effect only as contracts with the second defendant, and that the first defendant should not be under any liability. The plaintiffs entered into negotiations with agents for the first defendant, and amongst other things agreed with them upon extensions of time. However, those agents did not mention the liability of the second defendant, and the plaintiffs' claim against the second defendant became time-barred. The judge found that the agents for the first defendant knew that the plaintiffs mistakenly believed that the first defendant was the party to be sued, and deliberately encouraged that belief. He held that the first defendant was estopped from denying liability. The judge reached that decision by a number of different routes: first, that the agents were under a duty to alert the plaintiffs to the true facts, and that there was an estoppel by silence or acquiescence; secondly, that the first defendant by its agents had represented that it would not enforce its strict legal rights against the plaintiffs and there was therefore a promissory estoppel; and thirdly that it would be unconscionable for the first defendant to deny that it was the proper party to be sued, and there was therefore an equitable estoppel.
73. As to the first of those routes, Mr Wignall relies on the principle stated by Webster J at p465:

"… the duty necessary to found an estoppel by silence or acquiescence arises where 'a reasonable man would expect' the person against whom the estoppel is raised 'acting honestly and responsibly' to bring the true facts to the attention of the other party known by him to be under a mistake as to their respective rights and obligations".

74. As to the second, Mr Wignall relies on a passage at p466:

"In my view, whatever may be the precise meaning of the expression 'legal relationship', it applies to the relationship between two parties engaged in an exchange of correspondence in which one of them intends the correspondence to have legal effect in circumstances in which the other knows of that first party's intention and makes requests or purports to grant extensions of time which could only be of relevance to the first party if the correspondence between them affected their mutual rights and obligations".

75. Mr Wignall also relies on a passage at p468 in which Webster J indicates that an estoppel by convention may arise where parties act on an assumption as to the facts or the law, that assumption either being shared or made by one and acquiesced in by the other. In this regard, Mr Wignall invited my attention also to Thames Trains Ltd v Adams [2006] EWHC 3291 (QB).
76. It does not appear that the actual decision on the facts in The Henrik Sif has been doubted in subsequent case law, though Mr Johns invited my attention to some criticism of the decision by the learned editors of Chitty on Contracts (31^st ed, para 3-088).
77. It may be that the important feature of the case, and one which distinguishes it from the present, is that there was a contractual relationship between the plaintiffs and the first defendant, at least capable of giving rise to a cause of action, and the effect of the estoppel was that the first defendant was prevented from relying on a contractual provision which would have relieved it from liability in certain circumstances. Whether or not I am correct in that view, I am unable to regard The Henrik Sif as authority for the conclusion which Cs ask me to reach in this case. Webster J's decision did not have the effect that a cause of action was created, where none had existed before, against a party which did not have legal existence for much of the relevant period. No other authority has been cited to me which could support such a finding. It would be a finding which would have startling consequences: how, for example, could D2 have any insurance against a liability ascribed to it by operation of law in respect of a time when it had not been incorporated? In my judgment, to accede to Cs' submissions on this point would be to permit estoppel to be used as a sword rather than a shield, and I can find no ground on which I could properly do so.
78. I therefore reject Cs' submissions based on estoppel. That being so, it is unnecessary for me to consider the other submissions which Mr Johns advanced on that issue.
79. I turn to my decision as to the issue of concealment.
80. The starting point is section 32(1)(b) of the Limitation Act 1980. So far as is material, section 32 provides:

"32.— Postponement of limitation period in case of fraud, concealment or mistake.

(1) Subject to [subsections (3) and (4A)] below, where in the case of any action for which a period of limitation is prescribed by this Act, either—

(a) the action is based upon the fraud of the defendant; or

(b) any fact relevant to the plaintiff's right of action has been deliberately concealed from him by the defendant; or

(c) the action is for relief from the consequences of a mistake;

the period of limitation shall not begin to run until the plaintiff has discovered the fraud, concealment or mistake (as the case may be) or could with reasonable diligence have discovered it.

References in this subsection to the defendant include references to the defendant's agent and to any person through whom the defendant claims and his agent. …"

81. I accept the submission of Mr Wignall, based on Cave v Robinson, Jarvis & Rolf [2003] 1 AC 384, that concealment may take the form of non-disclosure as well as active concealment. Section 32(1) itself makes clear that the concealment (or non-disclosure) may be by the actions of an agent.
82. Mr Johns argued that D2 did not deliberately conceal any relevant fact: it was under no obligation to volunteer information as to D1's previous responsibility for the site, and its silence on that topic cannot be regarded as deliberate concealment. Moreover, on the authority of Williams v Fanshaw, Porter and Hazelhurst [2004] 1 WLR 3185, he argued that the party charged with concealment must not only be under a duty to speak, but must be aware of that duty and deliberately choose not to comply with it. Mr Johns further submitted that in any event, there can be no concealment of that which is known, and Cs did know that D1 had had responsibility for the site and that D2 was not incorporated until 2006. It follows, he submitted, that there can be no question of postponing the running of the limitation "clock" until after Cs "could with reasonable diligence have discovered" any relevant fact, because all relevant facts were actually known to them before the proceedings were commenced against D2 alone.
83. I am unable to accept these submissions. In my view, they are flawed by an unjustified conflation of knowledge on the part of Cs that D1 had at some stage had some involvement with the site, and knowledge that D1 was the appropriate defendant for part of the relevant period. As is implicit in the letter of 3^rd August 2012 (p172) to which I have referred, it would not be in any way unusual if D2 had taken over the site from D1 on terms that D2 assumed liability for any causes of action which may have arisen against D1. I accept the evidence of Miss Evans to which I have referred in paragraphs 10, 57 and 59 above. I reject Mr Johns' submission that Miss Evans is not entitled to give that evidence without a waiver of privilege: in my view she is entitled to state her own understanding of the correspondence she received, just as Mr Smith is entitled in his statement to state his understanding.
84. On the basis of Miss Evans' evidence, I am satisfied that Cs did not in fact know that any claim for damages for nuisance during the period 2005-2006 should be directed against D1. I reject as illogical the defendants' suggestion that Cs did know that relevant fact, but nonetheless chose not to sue D1, and to proceed instead against a party which they already knew could not be liable for that period. I can see no reason why I should infer such an attitude on the part of Cs who have since 2009 repeatedly made it clear that they seek compensation for, inter alia, nuisance in 2005 and 2006.
85. Why did Cs not know that fact? I am satisfied that it was because that fact was deliberately concealed from them by D2. I do not accept that this is merely a case of silence on the part of D2 in circumstances where there was no obligation to speak. In my judgment, D2 did speak, in the correspondence and documents which I have summarised above; and there was active misrepresentation by D2 which caused Cs to believe that D2 was the correct and only defendant for the whole of the relevant period of their claim. Without repeating the summary I have given of the course of correspondence and proceedings, I identify the following features which have particularly led me to that conclusion.
86. From the very outset, Cs were seeking confirmation that they had correctly identified the company which should be sued. The two companies from which that confirmation was sought were part of the same group, and the parent company Leo was aware of the enquiries. Only D2 instructed solicitors to respond, and their responses raised a number of lines of defence but conspicuously did not advance any suggestion that D2 was the wrong defendant for any part of the proposed claim.
87. That suggestion was never made until some 2 years 10 months after the claim against D2 was first intimated; and even then D2 did not identify D1 by name. Nor was D1 identified by name in the weeks which followed, despite a specific enquiry which was repeated several times, but to which there was not even the courtesy of a reply.
88. It is a striking feature of all the correspondence and other material which has been put before me, that at no time during that lengthy period did D2 ever say anything even to imply that another company was responsible for the site for a significant part of the claim. Given the tone and tenor of the correspondence, which at times might most kindly be described as tart, I find it very surprising that not even a passing remark conveyed that important fact to Cs' solicitors. It seems to me that at a number of points in the exchange of correspondence when one would have expected D1's involvement to be mentioned, references to "the defendant" became references to "the site".
89. I see no merit in the argument that it was only when D2 had to plead a formal statement of its case that it became necessary to turn its attention to the issue of when it took over the site. In one sense, of course, that is correct; but it overlooks the reality of the situation. One would expect any party to want to raise immediately the simple point that it was being accused of causing a nuisance at a time when it did not have any responsibility for the property concerned and did not even exist as a legal person. I agree with Miss Evans that one would expect the representatives of a prospective defendant to be keen to explain why that defendant could not be liable.
90. Moreover, in the contentious issues relating to pre-action disclosure, D2 never said that a substantial proportion of the documents sought related to a period when it was not responsible for the site. Mr Smith's explanation that D2 as the then-current site operator had possession of all the site records is no doubt correct, but it misses the point: one would expect D2 at least to mention that the onerous task with which they were faced included research into many documents which were not their own.
91. More generally, at no stage in these proceedings has there ever appeared to be any impediment to D2 having access to documents relating either to the period when D1 was responsible for the site, or to the period when D3 has been responsible. I accept Mr Wignall's submission that that feature gives rise to an inference of close collaboration between the three companies as members of the same group.
92. I accept Miss Evans' evidence that the conduct of D2 positively led her to believe that D2 was the only appropriate defendant. I also accept the submission that any solicitor in her position would have had the same belief. It can of course be said against her that she might have asked a specific question to ensure that D2 accepted its responsibility for the site throughout the period of the proposed claim, but it seems to me that in all the circumstances of this case, that is a counsel of perfection. In my judgment, over the course of the correspondence and proceedings from September 2009 to July 2012, D2's conduct as a whole deliberately gave rise to the affirmative impression that, whilst liability was denied on every other ground, there was no dispute but that Cs were pursuing the correct defendant. That, as it seems to me, is the conclusion which a solicitor would be likely to draw from the fact that D1 ignored all correspondence, whereas D2 instructed solicitors who thereafter advanced many lines of defence but never once made the simple point that D2 was not the appropriate defendant for a substantial part of the claim.
93. It is appropriate at this point to remind myself of the relevant provisions of CPR Part 1. I do so in its present form: the recent amendment does not affect the points which are relevant to my judgment.

"Part 1 - Overriding Objective

1.1 The overriding objective

(1) These Rules are a new procedural code with the overriding objective of enabling the court to deal with cases justly and at proportionate cost.

(2) Dealing with a case justly and at proportionate cost includes, so far as is practicable-

(a) ensuring that the parties are on an equal footing;

(b) saving expense;

(c) dealing with the case in ways which are proportionate-

(i) to the amount of money involved;

(ii) to the importance of the case;

(iii) to the complexity of the issues; and

(iv) to the financial position of each party;

(d) ensuring that it is dealt with expeditiously and fairly;

(e) allotting to it an appropriate share of the court's resources, while taking into account the need to allot resources to other cases; and

(f) enforcing compliance with rules, practice directions and orders. …

1.3 Duty of the parties

The parties are required to help the court to further the overriding objective."

94. Accepting as I do Miss Evans' evidence as to her state of knowledge and belief, it follows that at the time when Irwin J was managing these proceedings, she did not know that D1 was the appropriate defendant for part of the period of claim. D2 of course did know that fact. Irwin J had to consider the application for a GLO (in which the common issues were defined as I have indicated in paragraph 32 above), and the (contested) application for pre-action disclosure. In my view, the failure of D2 to inform the court that D1 was responsible for the site in 2005-2006 was a serious breach of D2's duty under CPR r1.3. No explanation at all has been given for the fact that Irwin J had to consider those applications in ignorance of any suggestion that the wrong defendant was being sued. It should be noted that in the material put before Irwin J, D2 was claiming credit for having done more than could reasonably be expected of it to assist Cs and the court, and yet this very relevant fact was never mentioned. Far from assisting the court to further the overriding objective, D2's conduct in my view ensured that the parties were not on an equal footing, and made it harder for the court to deal with the case justly. In respect of the claim for nuisance during 2005 and most of 2006, D2 had what it must have regarded as a cast-iron defence: it had no responsibility for the site at that time, did not exist for most of that time, and could not bear any liability. I can think of no good reason for D2 not to have put forward that defence at a very early stage, and no reason (good or bad) has been advanced on D2's behalf. I see no reason to doubt that if there had been any good reason for the delay in doing so, D2 would have wished to bring it to my attention. The practical effect of D2's delay was of course to enable D1 to advance a limitation defence which would not have been available to D1 if the true position had been explained sooner than it was.
95. In those circumstances I am driven to the conclusion that D2 deliberately concealed an obviously relevant fact from Cs and from the court.
96. Did D2 do so for its own purposes, or as agent of its sister company D1? On the balance of probabilities, the inference which I draw is that it acted for the benefit, and as agent, of D1. It is not, in my view, mere coincidence that the beneficiary of D2's concealment of a material fact was a company in the same group. If D1 and D2 had been commercial rivals, it is in my view unthinkable that D2 would have conducted itself as it in fact did. Moreover, I accept Mr Wignall's submissions to the effect that the disclosure process has shown D2 able and willing to act, when it chooses to do so, on behalf of all three defendants.
97. In making these findings, I do not of course overlook the evidence of Mr Smith. He was not required to attend for cross-examination, and so his evidence also stands unchallenged. I accept it, as far as it goes. But it cannot and does not contradict Miss Evans' statement of the effect upon her of the correspondence which she received. Nor can it provide any explanation for the illogicality of any suggestion that Cs already knew they should sue D1 in relation to 2005-2006, but chose instead to sue the wrong party. It seems to me to fall into the error of conflation, or confusion, to which I have referred in paragraph 83 above.
98. I emphasise that I limit myself to my finding of deliberate concealment by D2. I accept of course that counsel, when they drafted the skeleton argument to which I have referred in paragraph 34 above, were acting on the instructions given by D2, and I do not suggest that any criticism attaches to them. Clarke Willmott must also of course have acted on instructions. On the evidence before me, which involves no waiver of privilege by either side, it would not be fair to criticise them, and I do not do so. I feel bound to say, however, that I am troubled by their unexplained failure even to reply to a direct, and repeated, request for the name of the company which was responsible for the site in the early part of the relevant period.
99. In those circumstances, and for those reasons, I accept Cs' submission that there has been deliberate concealment of a relevant fact by D2 as agent of D1, and that pursuant to the Limitation Act 1980 s32(1)(b) the period of limitation for Cs' claim against D1 did not begin to run until Cs could with reasonable diligence have discovered that D1 was the appropriate defendant for any claim in respect of the period between 1^st January 2005 and 14^th November 2006. In my judgment the earliest date on which they could reasonably have done so was when they received the Generic Defence in July 2012.
100. I turn next to Cs' submissions as to CPR 19.5. The relevant part of that rule provides:

"19.5 Special provisions about adding or substituting parties after the end of a relevant limitation period

(1) This rule applies to a change of parties after the end of a period of limitation under-

(a) the Limitation Act 1980 ; …

(2) The court may add or substitute a party only if-

(a) the relevant limitation period was current when the proceedings were started; and

(b) the addition or substitution is necessary.

(3) The addition or substitution of a party is necessary only if the court is satisfied that-

(a) the new party is to be substituted for a party who was named in the claim form in mistake for the new party;

(b) the claim cannot properly be carried on by or against the original party unless the new party is added or substituted as claimant or defendant; or

(c) the original party has died or had a bankruptcy order made against him and his interest or liability has passed to the new party."

101. That rule was made pursuant to section 35 of the Limitation Act 1980, which so far as material provides:

"35.— New claims in pending actions: rules of court.

(1) For the purposes of this Act, any new claim made in the course of any action shall be deemed to be a separate action and to have been commenced—

(a) in the case of a new claim made in or by way of third party proceedings, on the date on which those proceedings were commenced; and

(b) in the case of any other new claim, on the same date as the original action.

(2) In this section a new claim means any claim by way of set-off or counterclaim, and any claim involving either—

(a) the addition or substitution of a new cause of action; or

(b) the addition or substitution of a new party; …

(3) Except as provided by section 33 of this Act or by rules of court, neither the High Court nor any county court shall allow a new claim within subsection (1)(b) above, other than an original set-off or counterclaim, to be made in the course of any action after the expiry of any time limit under this Act which would affect a new action to enforce that claim. …

(4) Rules of court may provide for allowing a new claim to which subsection (3) above applies to be made as there mentioned, but only if the conditions specified in subsection (5) below are satisfied, and subject to any further restrictions the rules may impose.

(5) The conditions referred to in subsection (4) above are the following—

(a) in the case of a claim involving a new cause of action, if the new cause of action arises out of the same facts or substantially the same facts as are already in issue on any claim previously made in the original action; and

(b) in the case of a claim involving a new party, if the addition or substitution of the new party is necessary for the determination of the original action.

(6) The addition or substitution of a new party shall not be regarded for the purposes of subsection (5)(b) above as necessary for the determination of the original action unless either—

(a) the new party is substituted for a party whose name was given in any claim made in the original action in mistake for the new party's name; or

(b) any claim already made in the original action cannot be maintained by or against an existing party unless the new party is joined or substituted as plaintiff or defendant in that action. …"

102. Cs contend that the amendment made on 26^th October 2012, so as to add D1 as a defendant, was justified by the terms of rule 19.5, and that accordingly the claim against D1 is deemed to have been made when the claim was issued on 23^rd December 2010, with the result that D1 cannot raise any defence of limitation. D1 contends that the amendment cannot be brought within the terms of that rule, and that accordingly D1 is to be treated as validly joined as a defendant but nonetheless entitled to its defence of limitation in respect of any cause of action accruing before 14^th November 2006.
103. It is common ground that the requirement set out in rule 19.5(2)(a) is satisfied, but there is an issue as to whether the addition of D1 as a defendant to the claim is "necessary" as defined in rule 19.5(3). There is also an issue as to whether, if the rule be satisfied, the court should exercise its discretion so as to permit the addition of D1.
104. In his submissions on behalf of Cs, Mr Wignall relied principally on paragraph (b) of rule 19.5(3), but did not abandon (a). He relied upon the statement of principle made by Leggatt J in Insight Group Ltd v Kingston Smith (a firm) [2013] PNLR 13. Having reviewed previous authorities, Leggatt J said at paragraph 96:

"The principle which I derive from those two decisions of the Court of Appeal is that the court has power to order substitution under s35(6)(b) and CPR r19.5(3)(b) if: (1) a claim made in the original action is not sustainable by or against the existing party; and (2) it is the same claim which will be carried on by or against the new party".

105. Mr Wignall submitted that the present case falls squarely within that principle: the claim originally made for damages for a nuisance by odour between January 2005 and November 2006 cannot be carried on by an existing party, Cs, unless they are permitted to make the same claim against D1. Mr Johns for his part relied on the actual decision in Insight Group Ltd v Kingston Smith (a firm), in which Leggatt J concluded that the new claim which was sought to be made in that case was not, on the facts, the same as the original claim. Mr Johns submitted that the same is true here: D1 and D2 are different alleged tortfeasors; the original claim was based on the factual foundation that D2 was responsible for the site in 2005-2006, whereas a new claim against D1 would be on the contradictory factual basis that D1 was responsible for the site during that period. Further, he argued, the original claim against D2 can be carried on. So far as rule 19.5(3)(a) is concerned, Mr Johns submitted that this is not a case of a mistake as to name: he argued that the 2009 correspondence to which I have referred shows plainly that Cs had identified two distinct companies, D1 and D2; that D2 was the appropriate defendant to the claim as endorsed on the claim form; and that if there had been any error by Cs, it was a mistake as to identity rather than a mistake as to name.
106. I note in passing that although Leggatt J decided the issue in respect of rule 19.5(3)(b) in the way on which Mr Johns relies, he concluded that there had been a mistake such as to bring that case within rule 19.5(3)(a).
107. As to the court's discretion, Mr Johns invited my attention to passages in the judgment of Lewison J in Fattal v Walbrook Trustees (Jersey) Ltd [2012] Bus LR Digest D7. In the context of an amendment under CPR 17.4, the judge said at para 41:

"In my judgment the discretion to allow an amendment after the expiration of a limitation period should not lightly or routinely be exercised in a way which would deprive the defendant of a limitation defence".

108. I am unable to accept Mr Johns' submissions. In my judgment rule 19.5(3)(b) applies to this case. "The claim", in this context, is the claim for damages for nuisance during the period 2005-2006. That is part of the claim which Cs initially brought, and that is what they wish to continue; but they are unable to continue it unless D1 is added as a defendant. The only difference between the two claims is that D2 has wrongly been sued as the company responsible for the site throughout. In my view, that does not alter the nature of the claim; but if I am wrong about that, then the distinction which Mr Johns draws can only be drawn because there was a mistake as to the name of the appropriate defendant. Thus even if (contrary to my conclusion) Mr Johns could succeed under paragraph (b), he could only do so on the basis that paragraph (a) applies to this case.
109. If I had not accepted Cs' submission that paragraph (b) applies this case, I would have been prepared to find that paragraph (a) applied to the circumstances of this case. It is to my mind entirely clear, and was known to both D1 and D2, that Cs wanted to sue the company responsible for the operation of the site from 1^st January 2005 to the present. A mistake as to whether that company was D1 or D2 at a particular time could, in my view, properly be regarded as a mistake as to name rather than as to identity. I do not accept that Cs had from an early stage identified D1 as the appropriate defendant, or even as an appropriate defendant.
110. For those reasons I conclude that the addition of D1 was an amendment which came within rule 19(5)(3)(b). If I am wrong about that, I would find in the alternative that the case comes within rule 19(5)(3)(a).
111. As to the exercise of my discretion, I bear very much in mind that the court should not lightly make an amendment which has the effect of depriving a party of a limitation defence. However, for reasons which are apparent in my ruling on the issue as to concealment of a material fact, I think it entirely clear that the amendment is consistent with the overriding objective of dealing with the case justly.
112. It follows that in my judgment Cs succeed both on the issue of concealment and on the issue of amendment, and on each of those grounds they are entitled to a declaration that their claim against D1 is not statute-barred.
113. This judgment is to be handed down in writing with no attendance by the parties. Thus far I have not heard any submissions as to costs. When the parties submit their suggested typing corrections (or nil returns), they must also indicate briefly whether they contend that issues of costs should be dealt with in writing or after oral submissions. There will have to be a case management conference in the autumn, and that will provide a convenient opportunity for any oral hearing as to costs which may be necessary.
114. Cs' solicitors must draw up a draft order reflecting this judgment, to be agreed if possible, and provide that also when responding to the draft judgment.

The Hon. Mr Justice Holroyde