Expert evidence is a crucial part of any case – and having permission to rely on such evidence revoked is not a position you want to find yourself in.  Solicitors and experts should always exercise extreme caution in communicating with each other and in particular where the expert is engaged in preparing a joint expert report. They should ensure their communications do not breach the expert's duties under CPR 35 and PD 35.  If communications are found to go beyond what is allowed, permission to rely on an expert's evidence could be swiftly revoked.   


In a recent judgment, ANDREWS V KRONOSPAN LTD, [2022] EWHC 479 (QB) the claimants' permission to rely on their expert's evidence was revoked after the court determined it had no confidence in the expert's ability to act in accordance with his obligations as an expert witness, following serious transgressions by the claimants' solicitors and the expert in their communications on drafts of the joint experts' report.  As a result of those communications, the court held that it was both appropriate, and not disproportionate, to revoke the claimants' permission to rely on their expert's evidence.  


As is often the case when permission to rely on expert evidence has been granted, the instructed experts for both parties had taken steps to prepare a joint expert report.  During discussions between the experts, it became apparent that the claimant's expert had sought, and been provided with, repeated assistance on the contents of the joint statement.

Of particular concern were comments which had been made on the draft joint statements by the solicitors: whilst the majority of these 68 comments related to typographical and formatting issues, at least 16 comprised "advice and suggestions as to content".  

The defendant made an application to revoke the claimants' permission to rely on the evidence of their instructed expert. 

The court was particularly concerned that the claimants' expert had held himself out to be an advocate for the claimant, and not an independent expert whose primary obligation was to the court.  Supporting this notion was the fact that the expert (i) had sent the first draft of the joint statement to the claimants' solicitors, unsolicited, and sought input from the solicitors on the draft (which was provided); (ii) sought to include evidence prepared for a conference with Counsel; and (iii) gave the claimants' solicitors information about the joint discussions – without informing his counterpart.  In addition, the claimants' solicitors themselves had failed to disclose the full extent of their communications with the claimants' expert (which included providing comments on drafts of the joint statement solely to the expert) and the expert had not explained the reason for his conduct. 

The claimant acknowledged that such conduct amounted to a "serious transgression of the rules" and the expert's duties undermined.  As a result, the court had no confidence in the expert's ability to act in accordance with his obligations as an expert witness and revoked the claimant's permission to rely on his evidence.  The court noted the importance of preserving the integrity of the expert discussion process, such that the court and the public can have confidence that the court's decisions are made on the basis of objective evidence.  That process had been tainted in this case.  


Ultimately, an expert owes his or her duty to the court and not any person from whom the expert has received instructions or by whom they are paid (CPR 35.3).   

Instructing solicitors should ensure at the outset of any instruction of experts that the provisions of CPR 35, PD 35 and the Guidance for the Instruction of Experts in Civil Claims 2014 are provided to, and fully explained to, an expert.  These provisions should be revisited during the course of an expert's instruction to ensure both solicitors and experts are in full compliance, and the expert's duties not undermined by the erroneous participation of solicitors in the joint experts' statement process.    

Moreover, solicitors should be mindful of the need for care in communicating with an instructed expert in general (and not just when a joint experts' statement is being prepared).  Even where an expert is preparing its report for its client, communications between solicitors and the expert on that report are potentially discloseable under CPR 35.10(4).  It is widely known that there is no privilege in instructions given to an expert (and indeed the formal letter of instruction is often appended to an expert's report) and so it follows that subsequent communications with an expert on those instructions also, in theory, fall to be disclosed.

Becky Green

Becky Green

Associate, Commercial Disputes

View profile