Expert evidence is often used during litigation to help the court understand matters where they do not possess the requisite technical or specialist knowledge on the area. Rules govern the use of experts in litigation and are contained in Part 35 of the Civil Procedure Rules (“CPR”) and Practice Direction 35.  

Expert evidence is not permitted as of right. The court’s permission is required to be able to rely on expert evidence and is only granted where expert evidence is “reasonably required”. Where permission has been granted by the court, an expert may be instructed by a solicitor, either solely or jointly with the other party, dependent on what has been agreed or ordered.  

It is important, however, to highlight the expert’s duties when providing their evidence. They do not have a duty to the instructing solicitor(s); experts have an overriding duty to the court. This means that, even if a solicitor has instructed an expert to provide evidence which they believe will further their client’s case positively, an expert cannot tailor their findings to state what the solicitor requires. Their opinion must be independent and must only cover areas that are within their expertise.  

When instructing experts, and indeed when experts carry out their instructions, regard must be made to ‘Guidance for the Instruction of Experts in Civil Claims 2014’. Within this guidance, several points are made regarding the duties of the expert, and the instructing solicitor(s), including the necessity for the expert to provide their opinion independently, and without pressure or influence from the litigation at hand.  

There are, however, circumstances where instructing solicitors have interfered with expert evidence and has rendered the expert’s work inadmissible. This has been recently considered by the High Court in Glover and another v Fluid Structural Engineers & Technical Designers Ltd and others [2024] EWHC 1257 (TCC).  

In this case, concerns were raised by the Sixth Defendant's expert, that the Glover's solicitor had appeared to have influenced significant changes made to Glover's expert's report. The Claimants' solicitors then made an application to court for a replacement expert. The Claimants' solicitors admitted to commenting on, and proposing amendments to, several drafts of the experts’ joint statements, as well as deleting certain metadata. They did, however, believe that it was permissible to make the joint statement accord with the pleaded issues, and had not intended to influence the expert.  

The Sixth Defendant argued against permission being granted. The Sixth Defendant also argued that extensive disclosure of privileged correspondence between the expert and the claimants' solicitors should be ordered, if permission to appoint a next expert were to be granted.  

Sitting as the High Court judge, Mr Simon Lofthouse KC held that since there was no case which reported on the same legal issue and facts as this case, permission would be granted to allow instruction of a new expert. The court has an overriding objective to the court to deal with cases justly and at a proportional cost. Therefore, in making this decision, Mr Lofthouse KC explained that, although there was no excuse for Glover's solicitor’s conduct, justice was best served by maintaining the trial date, if at all possible. Mr Lofthouse KC did follow this by stating that if the case was unable to achieve the trial date, permission would not have been granted.  

The reasons given to allow the instruction of a new expert also included the fact that the structural engineering evidence was central to the issues on liability. Therefore, without expert evidence, achieving a coherent trial would be difficult.  

The disclosure of the privileged material sought by the Sixth Defendant was refused. This was because privilege had already been significantly waived by the Claimants, on their own accord, in the statements provided to the court regarding the interference. If further disclosure was ordered, this would unnecessarily invade their privilege. Glover's solicitors were at fault and had sought to pre-empt any suggestion from the court or the defendant’s that the independence of the original expert had been compromised. There was also no suggestion that the opinion of the original joint statement was not the expert’s own view.  

In this case, the Claimants were ordered to pay costs thrown away due to the interference, plus 30% of the costs of considering the joint statement and expert report of the new expert, both on an indemnity basis.  

Legal disclaimer 

The matters contained within this article are intended to be for general information purposes only. This blog does not constitute legal advice, nor is it a complete or authoritative statement of the law in England and Wales and should not be treated as such. 

Whilst every effort is made to ensure that the information is correct, no warranty, either express or implied, is given as to its’ accuracy, and no liability is accepted for any errors or omissions. 

Before acting on any of the information contained herein, expert advice should always be sought.