Parties often seek to rely upon expert evidence, in particular evidence of foreign law, at interlocutory hearings. Commonly, an expert report will be adduced even though the expert is not expected to attend, or be cross-examined at, the hearing. Such hearings very often occur at an early stage in proceedings, in particular in applications for service out or disputing the jurisdiction of the English courts. Rarely, when this happens, has the party relying on the expert evidence already been before the court to seek permission to rely on such evidence. The question is, should they?
In relation to trials, CPR 35.4(1) provides that: “No party may call an expert or put in evidence an expert’s report without the court’s permission.” But as to interlocutory hearings, the CPR, White Book, and Commercial Court Guide are all silent.
Two recent judgments have expressed divergent views on this question. Deutsche Bank AG v Comune Di Savona concerned the scope of exclusive jurisdiction agreements contained in the International Swaps and Derivatives Association Inc. (ISDA®) Master Agreement. At paragraph 16, Longmore LJ said:
“The court asked the parties (1) whether the permission of the Commercial Court had been sought or granted for expert evidence to be adduced by Savona and (2) whether the principles of construction of documents in Italian law were different from those of English law for the purpose relevant to this case. The answers were (1) that no permission had been sought by Savona and (2) that there was no difference on the principles of construction between Italian and English law. I venture to think that, if permission had been sought and it had emerged that there was no difference in the principles of construction, permission would not have been granted and the jurisdiction application could have been disposed of rather more shortly and much less expensively. This is a matter which could usefully be considered by the Commercial Court Users Committee with a view to stating in the Commercial Court Guide that the permission of the court should be obtained before expert evidence of foreign law can be adduced on interlocutory applications. (The position at trial is, of course, catered for in CPR Pt 35.)”
By implication, therefore, the Court of Appeal was of the obiter view that the parties had been entitled to adduce this foreign law evidence without permission, but that this position ought to be reconsidered. At paragraph 39, Gross LJ explicitly endorsed Longmore LJ’s call for the Commercial Court Users Committee to take up the issue.
A different view was expressed by Baker J in B.B.Energy (Gulf) DMCC v Mohammed Hussein Al Amoudi and others. That case concerned an unsuccessful jurisdiction challenge on the grounds of lis alibi pendens (a lawsuit pending elsewhere). At paragraphs 49–51, the judge said (so far as is relevant):
In those circumstances and in any event, in my judgment it is a matter of significant regret that neither side identified, as undoubtedly they ought to have, that this was a heavy application that needed case management, not least because neither side had permission for reliance upon any expert evidence, permission being required for interlocutory hearings as much as for trials. […]
That is not a pedantic procedural concern on the part of the court in this case. In my view it has been a case, albeit that in the end these concerns have not become determinative of the application, in which the absence of either an agreed or directed-by-the-court review of what expert evidence was required, from what experts, answering what questions, has led to the exchange, through the service and counter-service of evidence, of an escalating volume of material not always addressing the same questions or analysing the case for the identification of the questions to be addressed in a consistent fashion and culminating in the late service of a second report by the claimant to which I referred earlier and in respect of which the defendants made a particular complaint. (Again, happily, the objection to the late-served second report has not proved to be of determinative importance in the application.)
[…] [I]n the order I make today, as well as dismissing the application, I shall give permission in accordance with Part 35 for each side respectively to rely, for the purposes of the application notice of 21 February 2018 only, on the various reports that were in fact served which can be recited in the order.
Baker J thus considered that permission was required to adduce expert evidence at an interlocutory hearing. In support of that view, he noted (as had the Court of Appeal in Savona) that there are good case management reasons for such a requirement: it allows the court to scrutinise the relevance, scope, and proportionality of expert evidence, thus reducing both costs and the use of court time.
As a matter of positive law, therefore, the position is not entirely clear. The question may well be considered by the appropriate rules committee, and clarified in subsequent editions of the White Book and the Commercial Court Guide.
In the meantime, parties would be well advised to assume that, following B.B.Energy, permission is indeed required. Such a requirement should not usually be especially onerous; the application can be included with the relevant application form to which it relates. It is to be expected that the court will rarely go to the trouble of assessing the application to adduce expert evidence separately from the substantive application to which it relates. Nonetheless, Savona provides an example of a case where expert evidence appeared to be unnecessary (although this may often be impossible to know until both parties’ expert reports have been prepared).
If Baker J’s approach is followed, parties face the risk that if permission is refused after reports have been prepared, the costs of those reports will be unrecoverable. For that reason, it will often be prudent to seek permission at the earliest possible stage (for example, when applying for permission to serve out, or when acknowledging service and indicating an intention to dispute jurisdiction) and if possible, before incurring significant costs. In doing so, parties may take note of Baker J’s suggestion that heavy jurisdictional applications may require case management, perhaps in the form of a dedicated case management conference at which any applications for expert evidence can be considered.