Suspicions are often aroused when an party wants to change expert mid-way through a case.  There is, usually, a requirement that before a court grants permission to instruct a new expert the previous report has to be disclosed. The case law is examined in detail in the judgment of His Honour Judge Grant in Coyne -v- Morgan [2016] EWHC B10 (24 May 2016). This is a useful exposition of the principles and case law which will be of help to anyone considering these issues.


  • The court has a wide discretion to impose terms when granting a part permission to call expert evidence. However when giving a party permission to replacement expert the discretion is usually exercised on condition that the report of the first expert is disclosed.
  • This principle applies when the parties have engaged in the relevant pre-action protocol process and the expert report was disclosed in the context of such process.
  • The courts discourage “expert shopping” however the discretion has to be exercised on a case by case basis.
  • The court will require strong evidence of expert shopping before imposing a term that the parties disclose documents other than the expert report itself.


An action was brought by the claimant home owner against defendant builders.  The experts for each party met and a defence and counterclaim was failed. There were various disagreements between the defendant and the expert. The defendants’ expert withdrew stating that he no longer had time to deal with the matter and he felt that the defendants no longer had confidence in him.


The defendants applied for permission to instruct a new expert.  The defendants’ argued that they were not “witness shopping” and the requirement to disclose the previous report should not apply. The claimant sought both the report and all relevant correspondence.


The judgment is useful in that it contains an analysis of the relevant rules and case law

  1. “CPR rule 35.4
Rule 35.4 provides, insofar as is relevant to this issue, as follows:
“(1) No party may call an expert or put in evidence an expert’s report without the court’s permission.
(2) When parties apply for permission they must provide an estimate of the costs of the proposed expert evidence and identify –
(a) the field in which expert evidence is required and the issues which the expert evidence will address; and
(b) where practicable, the name of the proposed expert.
(3) If permission is granted it shall be in relation only to the expert named or the field identified under paragraph (2). The order granting permission may specify the issues which the expert evidence should address.”
  1. The authorities
Counsel referred me to 3 cases in the course of their respective submissions. It is noteworthy that each of those cases concerns a different area of the law. The first in time was Vasiliou v Hajigeorgiou [2005] 1 WLR 2195; [2005] EWCA Civ 236; this concerned valuation evidence in a claim for breach of covenant in a landlord and tenant case. The second in time was Edwards-Tubb v JD Wetherspoon plc [2011] 1 WLR 1373; [2011] EWCA Civ 136; this concerned orthopaedic evidence in a personal injury case. The third in time was BMG (Mansfield) Ltd v Galford Try Construction Ltd; [2013] EWHC 3183 (TCC); this concerned architectural evidence in a construction case.
  1. In Vasiliou the head note records as follows:
” … the court made a (first) order giving both parties permission to “instruct one expert each in the specialism of restaurant valuation and profitability”. The defendant instructed an expert who visited the premises and prepared a draft interim report. Subsequently, deciding that he did not wish to rely on that report, the defendant instructed the second expert and sought the court’s permission to rely on his evidence. The judge found that although the (first) order … had not named the first expert, properly construed it permitted the defendant to instruct the first expert and no other, and that therefore the defendant required permission to rely on the second expert. The judge granted permission on condition that the defendant disclose the first expert’s draft report to the claimant.”
  1. The Court of Appeal held that, on its proper construction, the first order plainly and unequivocally identified the experts only by their field of expertise and not by name, and therefore the terms of that first order did not require the defendant to obtain permission to rely on the evidence of an expert other than the first expert. However, the Court of Appeal went on to consider what would have been the position if the first order had given permission for a named expert.
  1. In that context, the court was referred to it is earlier decision that year in Beck v Ministry of Defence (note) [2005] 1 WLR 2206. That was a personal injury case in which the claimant sought damages for psychiatric injury. Dyson LJ stated the facts in Beck as follows:
“24. … The court gave permission to each party to call one (unnamed) psychiatrist. The defendants’ first psychiatrist examined the claimant and produced a report which the defendants considered to be unsatisfactory. For this and other reasons, the defendants lost confidence in the expert. They asked the claimants solicitors for facilities for a further psychiatry examination by another expert. This request was refused.
  1. The defendants applied to the court for permission to change experts. No point seems to have been taken that the defendants did not need the permission of the court to change experts, because the court had not given permission by reference to named experts. The argument proceeded on the basis that the question was “whether it can ever be appropriate to allow a party to substitute one expert for another without, at some stage at least, being required to disclose the first expert’s report”: see paragraph 2 of the judgement of Simon Brown LJ. To that question Simon Brown LJ gave this resounding answer:
(26) “I do not say that there could never be a case where it would be appropriate to allow a defendant to instruct a fresh expert without being required at any stage to disclose an early expert’s report. For my part however I find it difficult to imagine any circumstances in which that would be properly permissible and certainly, to my mind, no such circumstances exist here.
Ward LJ said at paragraph (30):
“Nevertheless, expert shopping is to be discouraged, and a check against possible abuses is to require disclosure of the abandoned report as a condition to try again. I agree, for the reasons given by Simon Brown LJ, that the appeal should be allowed to that most limited extent.”
Lord Phillips MR said at paragraph … (35):
“The answer in this case, and in any case were a situation similar arises, is that proposed by Simon Brown LJ that the permission to instruct a new expert should be on terms that the report of the previous expert be disclosed. Such a course should both prevent the practice of expert shopping, and provide the claimants in the position of Mr Beck with the reassurance that the process of the court is not being abused. In this way justice will be seen to be done.”
  1. In paragraph 27 of his judgement Dyson LJ held as follows:
“… The court (in Beck) approached the issue that was before it on the footing that the defendants required permission in order to rely on the second expert. That is the basis on which we are approaching the second issue in the present case. The question of principle that was decided in Beck’scase was that the court has the power to give permission to a party to rely on a second (replacement) expert which it should usually exercise only on condition that the report of the first expert is disclosed.”
In similar fashion Dyson LJ held in paragraph 29 of his judgement:
“The principle established in Beck… is important. It is an example of the way in which the court will control the conduct of litigation in general, and the giving of expert evidence in particular. Expert shopping is undesirable and, wherever possible, the court will use its powers to prevent it. It needs to be emphasised that, if a party needs the permission of the court rely on expert witness B in place of expert witness A, the court has the power to give permission on condition that A’s report is disclosed to the other party or parties, and that such a condition would usually be imposed. In imposing such a condition, the court is not abrogating or emasculating legal professional privilege; it is merely saying that, if a party seeks the court’s permission to rely on a substitute expert, it will be required to waive privilege in the first expert’s report as a condition of being permitted to do so.”
  1. Edwards-Tubb was a personal injury case. The claimant followed the pre-action protocol procedure for personal injury claims by giving the defendants the names of three orthopaedic surgeons who the claimant might instruct, thus giving the defendant the opportunity to object to any of them. The head note continues the narrative:
“With no objection having been taken, the claimant instructed one of the nominated experts who examined the claimant and made a report. The defendant admitted liability for the claimant’s injury, and only the extent of the injury and quantum remained in issue. A few months later the claimant instituted proceedings with particulars of claim supported by the medical report of a different and un-nominated orthopaedic surgeon. That report mentioned that the claimant had seen an orthopaedic surgeon previously. The defendant, while recognising that the earlier pre-action report was a privileged document, applied for its disclosure on the ground that such disclosure should be a condition of the permission the claimant required …. The deputy district judge granted the application, so that reliance on the later report was conditional on disclosure … of the unused earlier report. The circuit judge allowed an appeal … discharging the condition on the basis that it impermissibly overrode the claimant’s privilege in respect of the earlier report.”
  1. The Court of Appeal held that the report of the first expert had been obtained in the course of, or context of, the relevant pre-action protocol procedure, and had thus been obtained in accordance with a procedure which had been authorised by the court. The head note stated:
” … while the pre-action expert report obtained by the claimant for the purposes of advice about, and the conduct of, litigation was a privileged document, which he was entitled to keep to himself, the prime duty of such an expert was unequivocally to the court, and once the party had embarked on the pre-action protocol procedure of co-operation in the selection of experts, there was no justification for not disclosing the report of an expert who had been put forward by that party as suitable … and had prepared a report; and that it was appropriate for the court to exercise the control afforded by rule 35.4 so as to maximise the information available to it, and to discourage expert shopping.”
  1. Hughes LJ gave the lead judgement of the court, with which both Lord Neuberger MR and Richards LJ agreed. He identified the question of principle involved in the appeal as follows:
“11. The question of principle which this case raises is whether the power to impose a condition on the grant of permission to rely on expert B can properly be employed to require the disclosure of the privileged report of expert A, and if so when. If this is proper, what is being done is not directly to override the privilege, because the claimant can elect to stand upon his right to it. Rather, it is presenting the claimant with a price which must be paid for the leave of the court to rely on expert B; that price is waiver of privilege in relation to expert A.”
Then, having reviewed the authorities including Beck and Vasiliou, and having decided that “… there is no difference in principle between the change of expert pre-issue and post issue” Hughes LJ identified the remaining issue as follows: “whether the imposition of a condition or disclosure of the type under discussion should be regarded as an unusual or exceptional order or should be the normal order.”
  1. Hughes LJ then gave his conclusions as follows:
“30. Authority apart, it seems to me that the imposition of a condition of disclosure is as justified in pre-issue as in post issue cases. I certainly accept that there may be perfectly good reasons for a party to wish to instruct a second expert. Those reasons may not always be that the report of the first expert is disappointingly favourable to the other side, and even when that is the reason the first expert is not necessarily right. That means that it will often, perhaps normally, be proper to allow a party the option, at his own expense, of seeking a second opinion. It would not usually be right simply to deny him permission to rely on expert B and thus force him to rely on expert A in whom he has for whatever reason lost confidence. But that is quite different from the question whether expert A’s contribution should be denied to the other party by the fact of who instructed him. An expert who has prepared a report for court is different from another witness. The expert’s prime duty is unequivocally to the court. His report should say exactly the same whoever instructed him. Whatever the reason for subsequent disenchantment with expert A may be, once a party has embarked on the pre-action protocol procedure of co-operation in the selection of experts, there seems to me no justification for not disclosing a report obtained from an expert who has been put forward by that party as suitable for the case, has been accepted by the other party as suitable, and has reported. Thus although the instruction of a medical expert is a matter almost of course in most personal injury cases, it is appropriate for the court to exercise the control afforded by rule 35.4 in order to maximise the information available to the court and to discourage expert shopping …
  1. For these reasons I would hold that the power to impose a condition of disclosure of an earlier expert report is available where the change of expert occurs pre-issue as it is when it occurs post issue. It is of course a matter of discretion, but I would hold that it is a power which should usually be exercised where the change comes after the parties have embarked upon the protocol and thus engaged with each other in the process of the claim….”
  1. In BMG the claimants claimed damages from both the contractor and the architect in connection with a fire which occurred in their shopping centre in October 2004. The head note, as reported in Westlaw, summarises the facts as follows:
“The claimants’ case was that the damage was much more extensive than it should have been owing to inadequate fire protection in the roof space and eaves canopies. Within days of the fire the claimant instructed an expert, an architect in his early 60s, who produced a report in April 2005. It was disclosed to the defendants in November 2006. Both defendants rejected the claim under the pre-action protocol process. After the claim was issued in October 2010, the parties exchanged various documents throughout 2011. In April 2012 the claimants’ expert met the defendants’ expert witnesses, and in May 2012 there was an unsuccessful attempt at mediation. Thereafter the claimants instructed their legal team to review its position including obtaining a second opinion of the correctness of expert advice; and that expert, who was by then nearing 70, withdrew as an expert.
The claimants applied for permission to call expert evidence from a fresh expert, and to amend their particulars of claim. The defendants submitted that the circumstances of the claimants’ expert’s withdrawal from the case were suspicious and that the claimants had known since May 2011 that he wished to retire from the case, but had deliberately withheld the information until it had instructed the new expert and obtained a fresh report. They requested, as a condition for the grant of permission to call a new expert, an order that the claimants disclose all undisclosed expert’s reports and any communications from the expert to the claimants containing his opinion on the issues in the claim.”
  1. The decision, again as reported in Westlaw, is summarised as follows:
“H8 Imposing a condition of disclosure of any previous reports ought to be the usual practice where the change of expert came after the pre-action protocol procedure had started. That principle applied to all reports, not only those prepared to use in litigation … The court’s power was not limited to ordering disclosure of an expert’s ‘final’ report; its powers extended to ordering disclosure of other reports containing the substance of the expert’s opinion.
There had to be a very strong case of expert shopping to justify a condition that solicitors’ attendance notes should be disclosed, otherwise there would be a significant and unjustified invasion of privilege and a considerable increase in litigation costs. The instant case was nothing approaching a strong case. At best there might be an appearance of expert shopping, but any such appearance was faint.”
  1. In his judgement Edwards-Stuart J found the following facts:
“14 …. Mr Roger Jowett, senior partner of BAP, said that following an unsuccessful mediation in May 2012 Mr Streeter told him that he did not want to continue with the case. Mr Jowett therefore offered to take over his role as an expert. … An associate solicitor at BLM said that at the time of the meeting it was still the claimants’ intention that Mr Streeter would continue to act as the claimants’ expert until the conclusion of the trial. She said that it was only on 29 May 2012, about one week after the mediation, that Mr Jowett told her that Mr Streeter no longer wished to act as the claimants’ expert.
15 There is no evidence before the court from Mr Streeter, and so I do not know whether his wish to retire was driven by his age or the fact (if it was a fact) that he had had a bruising time at the experts’ meeting and/or the mediation, or a combination of all three. On the face of it I can see nothing unreasonable about an expert who, approaching his 70th birthday, wants to be relieved of his duties as an expert in litigation that he could reasonably have expected to have been concluded some years earlier, and which had the immediate end in sight. It is well-known that giving contested evidence as an expert witness in a major trial can be very stressful.”
  1. In his judgement Edwards-Stuart J then held as follows:
“24. The decision of the Court of Appeal in Edwards-Tubb suggests that the imposition of a condition of disclosure of any previous reports should be the usual practice where the change of expert comes after the parties have embarked on the pre-action protocol procedure … that has clearly happened here: however, the difference is that Mr Streeter’s report of April 2005 was disclosed before that process began.
  1. I am prepared to accept that the conditions that the court can impose on a party applying for permission to call an expert are not limited to an expert’s ‘final’ report (meaning the report prepared for disclosure pursuant to CPR rule 35) but may extend to other reports containing the substance of the expert opinion: see Vasiliou at paragraph 29 to 31.
  2. What I regard as more problematic is disclosure of documents such as solicitors attendance notes of telephone calls with the expert which record (or purport to record) the substance of his opinions. There are at least two difficulties in the way of disclosure of such documents, which are of course privileged. The first is that they will probably not record the expert’s actual words, but rather the substance of what the solicitor understood the expert to say. The two may not be the same. The second is that the notes may well contain material that is not expert opinion: in this case for example Mr Streeter’s views on the other parties experts, and so on.
  3. While it may be said that the second difficulty can be overcome by appropriate redaction, as so often happens when confidential or even privileged documents have to be disclosed for one reason or another, this will not prevent the problem that always occurs with such disclosure; namely, that the disclosed passages very often have to be read in the context of the redacted passages in order for the meaning of the disclosed passages to be properly understood.
  4. Another problem which arises out of the first difficulty is that BLM may wish to check with Mr Streeter that what they have reported him as saying in a particular attendance note is correct. What is to be done if Mr Streeter does not wish to co-operate or does not agree that the note correctly records what he told the solicitors? It may be that he would have to make a witness statement and, if necessary, give evidence. It is hard to see how the costs of this exercise would be proportionate, even in the context of the case as substantial as this one.
  5. These considerations lead me to conclude that there would have to be a very strong case to justify a condition that such expert’s attendance notes should be disclosed in addition to any reports or draft report by the expert.
  1. In my view this is not a strong case of ‘expert shopping’ or anything near it …
  2. On one view, therefore, this is not a case of ‘expert shopping’ at all. The first expert had, perhaps not unreasonably in the circumstances, indicated that he wished to withdraw from the case. Mr Streeter had ceased full-time practice in 2008 and Mr Jowett says that by 2011 he was hoping that this litigation would be concluded by the end of that year and that, when agreeing to continue as the claimants expert following his retirement from full-time practice, Mr Streeter did not envisage that the case will continue for as long as it has.
  3. Whilst this is second-hand evidence, it is in my view inherently plausible …
  4. …. it seems to me that there has to have been ‘expert shopping’ or at least the very strong appearance of it, before disclosure of the type sought on this application should be ordered. I therefore declined to make an order of the type that the defendants seek.
  5. However I will order the claimants to disclose any other report or document provided to BLM by Mr Streeter in which he expressed opinions or indicate to the substance of such opinions on the matter in issuing these proceedings….”



“From those authorities I derive the following principles:
(1) The court has a wide and general power to exercise its discretion whether to impose terms when granting permission to a party to adduce expert opinion evidence: that is consistent with both the general way in which CPR rule 35.4 (1) is expressed, and the wide and general nature of the court’s case management powers, in particular those set out in CPR rule 3.1 (2) (m).
(2) In exercising that power or discretion, the court may give permission for a party to rely on a second replacement expert, but such power or discretion is usually exercised on condition that the report of the first expert is disclosed: see Dyson LJ at paragraphs 27 and 29 of his judgement in Vasiliou.
(3) Once the parties have engaged in a relevant pre-action protocol process, and an expert has prepared a report in the context of such process, that expert then owes a duty to the Court irrespective of his instruction by one of the parties, and accordingly there is no justification for not disclosing such a report:: see Hughes LJ at paragraph 30 of his judgement in Edwards-Tubb.
(4) While the court discourages the practice of ‘expert shopping’, the court’s power to exercise its discretion whether to impose terms when giving permission to a party to adduce expert opinion evidence arises irrespective of the occurrence of any ‘expert shopping’. It is a power to be exercised reasonably on a case-by-case basis, in each case having regard to all the circumstances of that particular case. See the approach of Hughes LJ inEdwards-Tubb, in particular at paragraph 30 of his judgement when referring to the range of circumstances which might lead to a change of expert, and Edwards-Stuart J in BMG; both those judges found that the fact that an expert had produced a report in the course or context of a relevant pre-action protocol process was a critical or decisive factor, rather than there having been any instance of ‘expert shopping’.
(5) The court will require strong evidence of ‘expert shopping’ before imposing a term that a party discloses other forms of document than the report of expert A (such as attendance notes and memoranda made by a party’s solicitor of his or her discussions with expert A) as a condition of giving permission to rely on expert B: see paragraphs 29-32 of the judgement of Edwards-Stuart J in BMG.
  1. That analysis enables me to deal with Mr Rumney’s submission, developed in paragraphs 3 to 5 of his note, that the court will only impose a condition of disclosing the report of expert A when giving permission to adduce expert opinion evidence from expert B in circumstances where there has been ‘expert shopping’. In my judgement, on their proper understanding, the authorities cited above do not show that the incidence of ‘expert shopping’ is a necessary or essential prerequisite which must be established before the court will exercise its general power or discretion whether to impose such a condition when giving a party permission to rely on a second replacement expert. I therefore reject Mr Rumney’s submission that the claimant would have to show that the defendant was expert shopping, in the sense of either rejecting the opinion of Mr Wells because they considered it to be unfavourable, or because they had lost confidence in Mr Wells, before the court could properly exercise its discretion to impose such a condition.
  1. There are two aspects of the facts, as they appear from the material presently before the court, which indicate that the court should impose a condition that the defendants disclose the draft report of Mr Wells dated 10 November 2015 as a condition of being permitted now to rely on the expert opinion evidence of Mr Mason. They are:
(1) the very fact that Mr Wells has already produced a draft report in the context of proceedings which had been issued previously on 4 March 2015; and
(2) the fact that Mr Wells had (a) discussed the expert issues in the case, and subsequently (b) attended a joint inspection with Mr Duckworth, who was his ‘opposite number’ i.e. the opposing expert of like discipline.
In my judgement either of the above factors indicates that the court should impose such a condition when granting such permission; the conjunction of the above factors makes it all the more so.


The judge did not, however, order disclosure of the attendance notes relating to the expert evidence.

  1. I now turn to consider the further point whether any other material such as attendance notes kept by the defendant solicitors should be disclosed. I gratefully adopt the analysis of Edwards-Stuart J in BMG in this regard. In his written submissions on behalf of the claimant at the CMC Mr Watkins submitted that:
“The defendants have declined to give any reasons (for deciding no longer to proceed with Mr Wells was their expert witness) and in such circumstances there is clearly a very strong inference of expert shopping to be drawn …”
However, on the facts as they unfolded at the CMC, I do not regard this as a “strong case of ‘expert shopping’. To the contrary: the defendant’s solicitors stated in their e-mail to Mr Wells of 2 December 2015 that they wanted him to continue as the defendants’ expert witness in this matter. Instead of the defendants stating that they had lost confidence in Mr Wells, it was Mr Wells who expressed concern that he perceived “… the defendants no longer had confidence in him …”: see Mr Rumney’s entry in his note for 13 January 2016. It may well be that there was a combination of reasons which led to Mr Wells deciding that he could no longer continue to act as the defendants expert witness. From Mr Rumney’s entry in his note for 19 November 2015 that would appear to be a combination of (a) Mr Wells considering himself to have been misled by the other side; (b) Mr Wells feeling unable to exclude reference in his report to what had been said in the course of ‘without prejudice discussions’, whatever he meant precisely by that expression; and (c) it then appearing to Mr Wells that the defendants lacked confidence in him.
  1. Conclusion
I have come to the following conclusions:
(1) As a condition of being permitted to adduce expert opinion evidence from Mr Mason, the defendants are to disclose the draft report of Mr Wells. However, any reference to or record of any without prejudice discussions between Mr Wells and Mr Duckworth (the claimant’s expert engineer) or any other person acting on behalf of the claimant, is to be redacted from that draft report before it is disclosed. What is to be disclosed is the substance of Mr Wells’ opinion on the expert issues in the case as set out in such draft report.
(2) The defendants are not required to disclose any attendance notes or memoranda or any other documents recording the substance of any conversation between Mr Wells and any member of the defendant’s solicitors.