Regular readers of this blog will need no introduction to the procedural issues that Mitchell -v- News Group Newspapers Ltd has given rise to already.  Procedural issues have arisen again and were considered by Mr Justice Warby (2014 EWHC 3590 (QB)). The judgment contains some interesting issues in relation to expert evidence; similar fact evidence in civil cases and the editing of witness statements by the court prior to trial.


The matter is set down for a trial of preliminary issues starting on the 17th November 2014. There are two defamation actions: Mr Mitchell against MGN and P.C. Rowland against Mr Mitchell.  (For ease of reference I will refer to Mr Mitchell as the claimant and the other parties as the defendant).


This is, essentially, a trial of who said what. However both parties wished to adduce expert evidence in relation to phonetics and field of vision/trajectory analysis.


This evidence related to the length of time that it would have taken for Mr Mitchell to speak the words alleged.

  1. The first question to address on any application to call expert evidence must be whether the evidence is admissible. Section 3 of the Civil Evidence Act 1972 provides that:

“3 (1) Subject to any rules of Court made in pursuance of this Act, where a person is called as a witness in any civil proceedings, his opinion on any relevant matter on which he is qualified to give expert evidence shall be admissible in evidence…

(3) In this section “relevant matter” includes an issue in the proceedings in question.”

  1. In Barings Plc v Coopers & Lybrand (No 2) [2001] EWHC 17 (Ch); [2001] PNLR 22 Evans-Lombe J reviewed the authorities and extracted from them at [45] the following propositions:

“expert evidence is admissible under section 3 of the Civil Evidence Act 1972 in any case where the Court accepts that there exists a recognised expertise governed by recognised standards and rules of conduct capable of influencing the Court’s decision on any of the issues which it has to decide and the witness to be called satisfies the Court that he has a sufficient familiarity with and knowledge of the expertise in question to render his opinion potentially of value in resolving any of those issues.”

  1. There was no contest between the parties on whether these requirements were met in relation to the two proposed experts, but it remains a matter for the court to decide. I had no difficulty in concluding that phonetics is a recognised academic discipline which encompasses the scientific study of rates of speech, and is governed by recognised standards of conduct. It is sufficiently clear that the chosen witnesses each possess sufficient knowledge to enable them to provide evidence of speech rates applicable to this case which has potential value to the trial judge. The issue to which such evidence would go is on any view the main issue in both actions. The account of the evidence that would be given satisfied me that it was capable of influencing the court’s decision on that issue.
  2. The court’s approach to deciding whether it should permit expert evidence, assuming it to be admissible, was also addressed by Evans-Lombe J in his analysis in the Barings case at [45], where he said this:

“Evidence meeting this test can still be excluded by the Court if the Court takes the view that calling it will not be helpful to the Court in resolving any issue in the case justly. Such evidence will not be helpful where the issue to be decided is one of law or is otherwise one on which the Court is able to come to a fully informed decision without hearing such evidence.”

  1. The court must also have regard to CPR 35.1 which provides that “Expert evidence shall be restricted to that which is reasonably required to resolve the proceedings.
  2. Here, the trial judge could arrive at a decision on the central issue in these cases without reference to expert or any analysis of speech rates, but instead by assessing the witnesses, their credibility, and the probabilities in the light of all the other evidence including the CCTV. It is naturally a matter for concern that the position adopted on one side of the issue is that evidence of this kind, if adduced, will be inconclusive. In that event, the evidence would not have been helpful but its admission would have been wasteful. It does not follow, however, nor could I take the view, that this evidence will not be helpful in resolving the issue justly.
  3. The case for Mr Mitchell, as explained by his Leading Counsel, is that the evidence would not only be helpful but it would be conclusive in his favour. I was in no position to dismiss that as a real possibility. Where a party to civil litigation credibly alleges that expert evidence he has obtained will show that his opponent’s case cannot be true, that must be a powerful factor in favour of permitting the evidence to be led. It also seemed to me that there is a real prospect that, if not conclusive, objective evidence of this kind would help the trial judge reach a conclusion as to the probabilities on the central issue. The evidence is potentially of value, perhaps very great value, in resolving the issues.
  4. The case for admitting the evidence is bolstered by the fact that these cases have an important public dimension and have attracted considerable public attention. It is highly desirable that their outcome should be one that commands public confidence. The process should not be vulnerable to the charge that one or the other party has been unreasonably denied an opportunity to lead evidence which, had it only been heard, would have altered the outcome.
  5. CPR 35.1 imposes a duty on the court to restrict expert evidence to that which is reasonably required. I do not, however, read this as imposing a test of absolute necessity. A judgment has to be made in the individual case, and it has to be made before the evidence is heard and evaluated. My conclusion was that evidence which it is credibly said could conclusively determine the single most important issue in the case meets the criterion in the rule.
  6. For those reasons I granted permission to each party to lead expert evidence on the issue identified above, Mr Mitchell’s evidence to come from Professor French and the evidence for NGN and PC Rowland to come from Professor Liberman. The order makes provision for the exchange of reports and for a meeting of the experts before trial, the purpose being to identify areas of agreement and disagreement.


Mr Mitchell wished to adduce an expert on optometrics on issues which related to the police officer’s field of vision. The defendant wished to instruct an expert in forensic visual reconstruction.

The judge was somewhat critical of the way in which the case for the defendant/police officer claimant had been conducted in this regard.

  1. which had been advertised by Mr Mitchell as the one in which he intended to obtain an expert report. The decisions of NGN and PC Rowland to instruct a witness in a different discipline, and to proceed with that instruction without any notice to Mr Mitchell until exchange of Skeleton Arguments also gave rise to understandable concern on behalf of Mr Mitchell.
  2. The primary focus of that concern was the risk that if permission was granted the experts might meet but as ships passing in the dark, neither having any knowledge of the other’s speciality. To the extent that the experts failed to agree, Mr Price would be hampered in or possibly disabled from properly testing his opponents’ evidence in this respect. It was submitted that even assuming Mr Postlethwaite to have relevant expertise it would be unfair to Mr Mitchell to give permission.
  3. Mr Browne and Mr Millar, in riposte, maintained that Mr Postlethwaite’s report fell within the scope of the issue that had been proposed as the subject of expertise, and was surely the better kind of evidence. Three dimensions are better than two, submitted Mr Browne. Counsel also complained that the nature of the report to be provided by Prof Whitaker remained wholly unclear. Mr Browne identified what he suggested were obscure specialities listed in Prof Whitaker’s CV, suggesting that on the face of it his expertise might be too refined to assist in what was in the end an exercise in reconstruction.
  4. This was clearly a highly unsatisfactory set of circumstances. I nonetheless decided to grant permission to both parties, for these reasons.
  5. Taking Mr Mitchell’s application first, the expertise of Prof Whitaker was apparent from his CV. I was satisfied that optometry and in particular peripheral vision are recognised fields of expertise, in relation to which Prof Whitaker is a qualified expert. The task he was to undertake was adequately described in Ms Middleton’s statement. I saw no reason to doubt that Prof Whitaker is able to perform that task. Mr Mitchell says that he can through this evidence demonstrate not just that PC Rowland probably did not but that PC Rowland cannot have seen visibly shocked members of the public before giving the warning. I could not at this stage reject that proposition, advanced through Leading Counsel. Even if the evidence falls short of proving impossibility there is a real prospect it will assist in resolving the probabilities. It appears to be evidence that is potentially of value in resolving this important issue. It is reasonably required for reasons similar to those identified above in respect of the phonetics evidence. It can be served in a short space of time, with sufficient time before trial.
  6. The application of PC Rowland and NGN was distinctly unattractive given their very late disclosure of a decision apparently made nearly two months earlier to instruct an expert in an entirely different discipline from the one which they knew Mr Mitchell had chosen. The potential for unfairness to Mr Mitchell was a significant consideration. However, Mr Postlethwaite appeared to me to possess considerable expertise, recognised by courts on a number of occasions, in reconstructing events with precision. He was in my judgment sufficiently qualified within the meaning of s 3 of the Civil Evidence Act 1972 to provide the court with opinion evidence, by means of a report and 3D computer graphics, on the issue of what PC Rowland could have seen. I found that his evidence would be potentially helpful in resolving whether PC Rowland could have seen members of the public and if so where and when. If his evidence was excluded the court would be left with no cross-check on Prof Whitaker’s conclusions. I concluded that any risk of unfairness to Mr Mitchell could be adequately catered for by the court making due allowance in assessing the weight to give to Mr Postlethwaite’s conclusions, to the extent they differ from those of Prof Whitaker.
  7. I add that PC Rowland and NGN have made no complaint of being hampered or disabled from cross-examining Prof Whitaker on account of having no optometrist of their own. They could hardly make such a complaint in the circumstances. Should any claim be made in future to recover costs they incurred in obtaining help from an optometrist for the purposes of cross-examination that would have to be looked at very carefully indeed.


One interesting aspect of the judgment was the judge’s consideration of  the applications to exclude evidence.

1. The defendant had pleaded that Mr Mitchell had, on previous occasions, been rude about police officer’s conduct.

2. Mr Mitchell made an application to exclude evidence of these issues.


This is an issue that sometimes, but rarely, crops up in civil proceedings. There is a useful review of the principles.


  1. The controversial evidence relates to incidents other than the one which is at the centre of both actions. It was common ground at the hearing that the relevant principles are those concerned with the admission in civil cases of evidence of “similar facts”, and that those principles are to be found in the decision of the House of Lords in O’Brien v Chief Constable of South Wales Police [2005] 2 AC 534. There the House identified a two stage process, holding that the test of admissibility of similar fact evidence in a civil case is one of relevance only; if that test is satisfied the court will consider whether the evidence should be admitted, as a matter of case management.
  2. Lord Bingham said this at [3]-[4]:

“3 Any evidence, to be admissible, must be relevant. Contested trials last long enough as it is without spending time on evidence which is irrelevant and cannot affect the outcome. Relevance must, and can only, be judged by reference to the issue which the court (whether judge or jury) is called upon to decide. As Lord Simon of Glaisdale observed in R v Kilbourne[1973] AC 729, 756:

“Evidence is relevant if it is logically probative or disprobative of some matter which requires proof … relevant (i e logically probative or disprobative) evidence is evidence which makes the matter which requires proof more or less probable.”

4 That evidence of what happened on an earlier occasion may make the occurrence of what happened on the occasion in question more or less probable can scarcely be denied. If an accident investigator, an insurance assessor, a doctor or a consulting engineer were called in to ascertain the cause of a disputed recent event, any of them would, as a matter of course, inquire into the background history so far as it appeared to be relevant. And if those engaged in the recent event had in the past been involved in events of an apparently similar character, attention would be paid to those earlier events as perhaps throwing light on and helping to explain the event which is the subject of the current inquiry. To regard evidence of such earlier events as potentially probative is a process of thought which an entirely rational, objective and fair-minded person might, depending on the facts, follow. If such a person would, or might, attach importance to evidence such as this, it would require good reasons to deny a judicial decision-maker the opportunity to consider it. For while there is a need for some special rules to protect the integrity of judicial decision-making on matters of fact, such as the burden and standard of proof, it is on the whole undesirable that the process of judicial decision-making on issues of fact should diverge more than it need from the process followed by rational, objective and fair-minded people called upon to decide questions of fact in other contexts where reaching the right answer matters. Thus in a civil case such as this the question of admissibility turns, and turns only, on whether the evidence which it is sought to adduce, assuming it (provisionally) to be true, is in Lord Simon’s sense probative. If so, the evidence is legally admissible. That is the first stage of the inquiry.”

  1. Lord Phillips identified the test of admissibility thus, at [53]: “I would simply apply the test of relevance as the test of admissibility of similar fact evidence in a civil suit. Such evidence is admissible if it is potentially probative of an issue in the action.” On this and other issues Lords Steyn, Rodger and Carswell agreed with Lords Bingham and Phillips.
  2. The main considerations affecting the second, case management stage were identified by Lord Bingham at [5]-[6]:-

“5 The second stage of the inquiry requires the case management judge or the trial judge to make what will often be a very difficult and sometimes a finely balanced judgment: whether evidence or some of it (and if so which parts of it), which ex hypothesi is legally admissible, should be admitted. For the party seeking admission, the argument will always be that justice requires the evidence to be admitted; if it is excluded, a wrong result may be reached. In some cases, as in the present, the argument will be fortified by reference to wider considerations: the public interest in exposing official misfeasance and protecting the integrity of the criminal trial process; vindication of reputation; the public righting of public wrongs. These are important considerations to which weight must be given. But even without them, the importance of doing justice in the particular case is a factor the judge will always respect. The strength of the argument for admitting the evidence will always depend primarily on the judge’s assessment of the potential significance of the evidence, assuming it to be true, in the context of the case as a whole.

6 While the argument against admitting evidence found to be legally admissible will necessarily depend on the particular case, some objections are likely to recur. First, it is likely to be said that admission of the evidence will distort the trial and distract the attention of the decision-maker by focusing attention on issues collateral to the issue to be decided. This is an argument which has long exercised the courts (see Metropolitan Asylum District Managers v Hill (1882) 47 LT 29, 31, per Lord O’Hagan) and it is often a potent argument, particularly where trial is by jury. Secondly, and again particularly when the trial is by jury, it will be necessary to weigh the potential probative value of the evidence against its potential for causing unfair prejudice: unless the former is judged to outweigh the latter by a considerable margin, the evidence is likely to be excluded. Thirdly, stress will be laid on the burden which admission would lay on the resisting party: the burden in time, cost and personnel resources, very considerable in a case such as this, of giving disclosure; the lengthening of the trial, with the increased cost and stress inevitably involved; the potential prejudice to witnesses called upon to recall matters long closed, or thought to be closed; the loss of documentation; the fading of recollections. It is, I think, recognition of these problems which has prompted courts in the past to resist the admission of such evidence, sometimes (as, perhaps, in R v Boardman [1975] AC 421) propounding somewhat unprincipled tests for its admission. But the present case vividly illustrates how real these burdens may be. In deciding whether evidence in a given case should be admitted the judge’s overriding purpose will be to promote the ends of justice. But the judge must always bear in mind that justice requires not only that the right answer be given but also that it be achieved by a trial process which is fair to all parties.”

  1. Lord Phillips’ approach was similar. At [54]-[56] he identified considerations which the court would need to have in mind in deciding whether as a matter of discretion to admit evidence or cross-examination as to collateral issues. These included the need for proportionality and expedition, whether the evidence is likely to be relatively uncontroversial, and whether its admission is likely to create side issues that unbalance the trial and make it harder to see the wood for the trees. He added that the judge would have well in mind the considerations which concerned the House of Lords inMetropolitan Asylum District Managers v Hill 47 LT 29.
  2. In that case, as pointed out by Lord Phillips at [44]-[45], the House had expressed concern at the prospect that the admission of evidence of collateral facts might prevent trials from being kept within a practical and manageable compass. With this concern in mind, Lord Watson had proposed that two conditions would need to be satisfied before collateral facts should be admitted as evidence to prove a matter in dispute. The first was that the collateral fact would “when established be capable of affording a reasonable presumption or inference as to the matter in dispute“. The second was that the evidence should be “reasonably conclusive [as to the collateral fact] and will not raise a difficult and doubtful controversy of precisely the same kind as that which the jury have to determine”.
  3. Mr Price placed considerable emphasis on these two conditions in his submissions. I accept of course that the probative value of the alleged collateral facts and the likely nature, scope and outcome of any dispute about them are important considerations, when making case management decisions. I do not consider, however, that these passages from the speech of Lord Watson are to be treated as if they were in a statute or represent rigid rules governing the exercise of the discretion to admit evidence of relevant collateral facts. As Lord Phillips observed in O’Brien at [46], what Lord Watson was doing in this passage was “contemplating that the trial judge would have a discretion to shut out evidence of collateral facts in the interests of keeping the trial manageable. He was not propounding an inflexible rule of admissibility.”



  1. Mr Browne submitted that it was a conclusive answer to Mr Mitchell’s application that he had not objected when these matters were first raised in PC Rowland’s Reply on 23 July 2014, and that the matters had also been pleaded by NGN before objection was raised. I did not find that a persuasive submission. It was not said that Mr Mitchell’s delay had caused prejudice to Mr Rowland or NGN, nor does that appear likely. Mr Mitchell’s objection to reliance on evidence of these matters has been expressed since 22 September 2014 when he served his Amended Reply in the NGN action. That was some three weeks before the exchange of witness statements. All the witness statements relied on by NGN and PC Rowland in support of the “similar incidents” were made and served after that. Even if some prejudice had been caused in the form of additional cost that ought not to be a basis for admitting evidence which on a proper analysis is irrelevant, or evidence which it would otherwise be appropriate to exclude as a matter of case management. I therefore considered the merits of the application.
  2. The starting point must be to consider relevance, for which purpose it is necessary to identify “the matter which requires proof“, to use Lord Simon’s words in R v Kilbourne. Mr Price’s submission was that the matter requiring proof is, quite simply, that Mr Mitchell used the “toxic words” attributed to him by PC Rowland.
  3. Whether Mr Mitchell used the “toxic words” is of course central but (assuming the matter is not resolved by expert evidence) that allegation must be considered in its context. To assess whether it is probable that Mr Mitchell spoke those words the court will need to consider the whole sequence of events at the Downing Street gates that evening, and the differences between the competing accounts of Mr Mitchell’s behaviour. There are areas of dispute about the detail that may be important.
  4. NGN’s Defence alleges that Mr Mitchell approached the Downing Street gates identifying himself as Chief Whip and demanded to be allowed to leave through the main gates. He continued to do so when told that according to security rules officers could not open the main gates for cycles, so it is alleged, ignoring requests to comply with the rules. It is said that when PC Rowland approached him he seemed agitated, continued to refuse to comply with requests to leave by the side pedestrian gate, reiterating his status as Chief Whip. He is alleged to have then walked towards the side gate, lost his temper and spoken the “toxic words”, and then left announcing that PC Rowland hadn’t heard the last of it.
  5. Mr Mitchell denies ignoring officers’ requests, or “demanding” to be allowed to cycle out. He says he “simply and politely asked to be allowed to do so” and that he said “please open the gates. I am the Chief Whip; I work here at number 9“. He denies losing his temper, though he does admit to becoming “frustrated at being obstructed” and to swearing about the officers under his breath. He makes no concession that he was angry.
  6. PC Rowland’s case is to the same effect as that of NGN. He adds that throughout the incident he was calm, but Mr Mitchell “appeared agitated and was unjustifiably rude and high-handed” to PC Rowland in particular. A witness summary in respect of one of the other officers at the Downing Street gates that night states that Mr Mitchell was “clearly furious“.
  7. Having identified areas of difference in the rival cases, the next question is whether, in relation to those differences, the “similar incidents” are probative of the case for NGN and PC Rowland. Mr Price’s submission was to the effect set out at 50 and 51 above: that the incidents are equivocal or neutral as between the two versions of events, and take the matter no further than the admission and averment in Mr Mitchell’s Amended Reply. Mr Millar submitted that the incidents are evidence of a propensity or tendency on Mr Mitchell’s part to push at the enforcement of security rules by junior police officers and to react adversely – testily or angrily – and to threaten consequences. Although the degree of anger and the degree of offensiveness were greater on 19 September 2012 than on previous occasions, his reactions bore similarities to his behaviour on previous occasions. To that extent these were incidents of an “apparently similar character” to the incident in issue. He submitted that, looked at as a body of evidence, the evidence of those incidents goes beyond what Mr Mitchell has been prepared to admit and that if established they are potentially probative of the case for NGN and PC Rowland.
  8. I accepted the submissions of Mr Millar, in respect of a majority of the alleged incidents. I asked myself whether the evidence, assuming it provisionally to be true, might lead to the conclusion that events on the evening of 19 September 2012 were more likely to have unfolded in the way alleged by PC Rowland and NGN, rather than as alleged by Mr Mitchell. I concluded that the answer was that it might.
  9. Looked at collectively the evidence of Mr Mitchell’s encounters with police over cycle access at the Palace of Westminster, and cycle entry to and exit from Downing Street portrays a course of dealings in which Mr Mitchell has repeatedly asserted his status, engaged in confrontation, and, on a number of occasions, behaved in a rude and condescending way to police officers. One of the alleged incidents – the one of November 2005 – involves an explicit proclamation that he was too important to stop for the officer, and a direct insult addressed to the officer involved, under minimal if any provocation. The alleged incidents in Africa, if true, might show a hot temper, the use of foul language when provoked, a strong sense of superior status, and a condescending attitude to police officers.
  10. The evidence seemed to me potentially to throw light on Mr Mitchell’s attitude and reaction when impediments are placed in his way by police officers and to show a more complex picture, materially different from Mr Mitchell’s version of events on 19 September 2012 and from the occasional impatience and short temper and very occasional rudeness on other occasions which is admitted to by Mr Mitchell.
  11. There were, however, six allegations that I ruled out as they seemed to me to fall short of the threshold of potential probative value. Allowing for the two alleged incidents which Mr Mitchell accepts are relevant for other reasons, that left nine disputed “similar incidents”, involving some eleven witnesses.
  12. As to the exercise of the discretion to exclude relevant evidence, Mr Price submitted that there was potential for unfairness to Mr Mitchell as he could not remember most of the incidents, and that the probative value of the evidence did not outweigh the unfair prejudice which its admission would cause. He said that the evidence raised collateral issues which could not fairly be resolved with confidence. He conducted a detailed analysis of each alleged incident with a view to illustrating these points.
  13. In the course of his submissions Mr Price invited me to reach conclusions as to the credibility of at least some of the allegations against Mr Mitchell. He submitted, for instance, that the suggestion that Mr Mitchell had said in November 2005 that he was too important to stop for a police officer “simply lacks any credibility“. In relation to the evidence of incidents of 2011 in Africa he submitted that the officer who claims to have witnessed the events “is not a witness on whom the court can rely“.
  14. My conclusion was that the evidence that I found to be relevant should be admitted. I did not consider it appropriate to rule on issues of credibility at the PTR. The evaluation of the evidence is a matter for trial. However, I did not believe the trial would be distorted or unbalanced by the admission of this evidence. The incidents alleged were all relatively brief, and the evidence in support of them quite narrowly confined. The evidence, if properly managed at trial, should not take up a great deal of time.
  15. I did not consider there would be unfair prejudice to Mr Mitchell. He has been able to plead a positive case as to the nature and extent of his adverse reactions to what he perceived as obstruction from police officers. His witness statement addresses specifically the allegations about the November 2005 incident at the Palace of Westminster and about his conduct on the African visits. Mr Price’s submissions showed that he is able on behalf of Mr Mitchell to test much of the evidence by reference to documents. The trial judge can give appropriate weight to the evidence, making due allowance for the passage of time and any restrictions on Mr Mitchell’s ability to challenge what is said. Moreover, Mr Mitchell will be able to rely on the substantial number of witness statements he has obtained and served containing evidence to the effect that he is habitually courteous and respectful towards others, including the police. This is an aspect of the evidence to which I refer further below.


The judge considered an application that some of the evidence from Mr Mitchell and his witnesses should be excluded or deleted.

Objections to witness statements

  1. NGN and PC Rowland applied for a ruling that parts of the witness statements of Mr Mitchell and his witnesses should be removed on the grounds that they were irrelevant to the preliminary issues, or otherwise inadmissible. As I said at the time, this was an unusual application in relation to what will be a trial by judge alone. Nonetheless I heard the application, and ruled on issues of principle. I concluded that evidence relevant only to the damage allegedly caused by the words of which Mr Mitchell complains had no bearing on the preliminary issues, which do not include any issues of damage. As there were substantial passages covering this topic, with no other apparent relevance, I concluded that in the circumstances of this case there should be an editing process in relation to the versions of the statements for use at trial. For the purposes of the trial, the attention of the parties, the judge, reporters and observers should be focused on what is relevant to the issues being tried.
  2. Some issues of detail were left over to allow for written submissions on behalf of Mr Mitchell. Having since had those submissions I am able to provide final conclusions. So far as Mr Mitchell’s own statement is concerned, the passages which should be omitted from the version made available to the public at trial and to the trial judge are those objected to by NGN and PC Rowland, with the exceptions identified in the schedule to this judgment. As for the statements of Mr Mitchell’s witnesses, my ruling was that passages containing assessments, based on their knowledge of his behaviour, of the likelihood of Mr Mitchell using the words alleged should not be ruled out of their statements. The dividing line between what is and is not admissible in this respect is not always clear cut. It is appropriate to leave until trial the assessment of where that line is drawn. That leaves controversy over just one paragraph in the statement of Lord Turner. Mr Mitchell accepts, in the light of my ruling, that this paragraph should be edited. The passages to remain are identified in the schedule.


It will be interesting to see, at trial, what importance and weight opinion evidence is given.  This is something considered in

It will be interesting to see if these issues need re-visiting when the judgment is given in the substantive trial later this month.