Practice Direction 35: Instructing an Expert Witness in the UK

Practice Direction 35 (PD 35) provides detailed guidance for solicitors on instructing expert witnesses and presenting expert evidence within the Civil Procedure Rules (CPR) in England and Wales. Adhering to these rules is fundamental to ensuring that expert evidence is admissible, reliable, and serves the court's overriding objective.

The Role of Practice Direction 35 in Expert Evidence

CPR Part 35 and its accompanying Practice Direction govern the use of experts and their evidence in civil proceedings. Their purpose is to ensure that expert evidence is properly controlled, proportionate, and assists the court in a balanced way, rather than advocating for one party. For solicitors, understanding PD 35 is not merely a formality; it is essential for avoiding potential challenges to expert evidence, managing costs, and meeting court deadlines.

Overriding Duty to the Court

One of the most critical aspects of PD 35 is its emphasis on the expert's overriding duty to the court. An expert's primary responsibility is to provide independent, unbiased assistance to the court, not to the party instructing them. This duty overrides any obligation to the instructing party, even if it might conflict with the interests of that party. Solicitors must ensure experts understand this principle from the outset, as any perceived bias can severely undermine the expert's credibility and the weight given to their evidence.

Proportionality and Permission

PD 35 also stresses proportionality. The court's permission is generally required to adduce expert evidence, and the court will consider whether expert evidence is reasonably required to resolve the proceedings. Factors include the value of the claim, the complexity of the issues, and the amount of money at stake. The court has powers to limit the issues on which expert evidence is called, the number of experts, and the sphere of expertise.

Key Requirements When Instructing an Expert

When a solicitor instructs an expert witness, several strict requirements set out in PD 35 must be followed. These ensure the expert is properly briefed, understands their duties, and produces a report suitable for court. Failure to adhere to these can lead to significant delays, costs sanctions, or even the exclusion of the expert's evidence.

Clear Instructions and Scope

The instructions provided to an expert must be clear, comprehensive, and in writing. PD 35, paragraph 3.1 emphasises that instructions should:

• Identify all the material facts with which the expert is asked to deal.
• Specify the questions the expert is asked to answer.
• Instruct the expert to specify any assumptions made.
• Inform the expert of the existence of any factual disputes relevant to their opinion.
• Ensure the expert is aware of their overriding duty to the court.

It is good practice to include all relevant documentation and identify any particularly sensitive information. For complex cases, a detailed letter of instruction can help define the scope of the expert's work and align expectations.

Expert's Report Format and Content

Every expert report must comply with the format and content requirements of PD 35, paragraph 3.2. This includes:

• Details of the expert's qualifications and experience.
• Details of any literature or other material relied upon.
• A summary of the facts on which the opinion is based.
• The expert's opinion and the reasons for it.
• A summary of the conclusions.
• A statement of compliance with the expert's duty to the court (the 'statement of truth').
• An indication of whether the expert's instructions are incomplete, or whether they are unable to give a conclusive opinion without further information or instructions.

The expert must also sign a statement confirming they understand their duty to the court and have complied with it. (See CPR 35.10 for report contents).

Discussions Between Experts

PD 35, paragraph 9, provides for discussions between experts. The court may direct experts to discuss their evidence to identify and narrow the issues, and where possible, reach agreement. The purpose is not to bind the parties, but to clarify matters for the court. A joint statement must be prepared outlining areas of agreement and disagreement, with reasons. Solicitors should prepare their experts thoroughly for such discussions, ensuring they understand the legal context and their continuing duty to the court.

Preparing Your Expert for Court and Cross-Examination

Even a well-prepared report may be challenged in court. Experts need to be robust and articulate in defending their opinions under cross-examination, whilst maintaining their independence.

Understanding Court Procedures

Solicitors must ensure their experts are familiar with court procedures, including giving oral evidence and the formalities involved. This may involve briefing the expert on the likely areas of cross-examination, the general conduct in court, and the importance of precise and measured responses. An expert who is unfamiliar with the court environment may appear less credible, regardless of their expertise.

Admissibility Challenges

Opposing parties may challenge the admissibility of expert evidence on several grounds, including:

• Lack of independence: If the expert is perceived as biased towards the instructing party.
• Insufficient qualifications: If the expert's qualifications or experience do not directly relate to the issues.
• Lack of basis: If the expert's opinion is not logically reasoned or supported by the facts or accepted methodology.
• Non-compliance with PD 35: Formal errors in the report's content or format.

These challenges can cause significant delays and added costs. Proactive compliance with PD 35 mitigates these risks.

Consequences of Non-Compliance

Non-compliance with PD 35 can have serious repercussions for the instructing solicitor, the expert, and ultimately, the client's case. The court has a range of powers to address non-compliance.

• Exclusion of evidence: The court may refuse permission for the expert evidence to be relied upon entirely.
• Cost sanctions: The party in default may be ordered to pay the costs of the application to deal with the non-compliance, or even all the expert costs.
• Delay: Applications to cure non-compliance or to challenge evidence inevitably lead to delays in the proceedings.
• Reputational damage: For both the solicitor and the expert, repeated non-compliance can damage their professional standing.

Solicitors must remain vigilant throughout the process of instructing and relying on expert evidence to avoid these pitfalls. Timely and appropriate instruction is key. If you find yourself needing to source an expert quickly under tight deadlines, remember that services like ourselves specialise in locating qualified professionals who understand these requirements. You can submit a confidential request on our platform.

FAQ

What is the primary duty of an expert witness under CPR Part 35?

An expert witness's primary duty is to the court, not to the party instructing them. They must provide independent, unbiased, and objective evidence to assist the court in its decision-making process.

Can I instruct an expert without the court's permission?

No, generally, expert evidence requires the court's permission under CPR 35.4. Seeking permission early is crucial, and the court will consider proportionality and whether the evidence is reasonably required.

What happens if an expert changes their opinion?

If an expert changes their opinion after submitting their report, they must promptly notify the instructing party and, through them, all other parties and the court. The expert should also provide a brief new report or addendum explaining the change and the reasons for it.

How does Practice Direction 35 affect joint expert instructions?

PD 35 encourages the use of a single joint expert where appropriate. If parties agree, or the court directs, a single expert can be instructed by both sides, which can save costs and avoid conflicting expert evidence. Their duty to the court remains paramount.

What is a 'statement of truth' in an expert report?

A statement of truth is a declaration at the end of an expert report, signed by the expert, confirming that they understand their duty to the court, have complied with that duty, and that the facts stated in the report are true and their opinions are genuinely held. This is a mandatory requirement under PD 35, paragraph 3.2 (9).

Conclusion

Compliance with Practice Direction 35 is not just a procedural hurdle; it is integral to the ethical and effective presentation of expert evidence in UK civil litigation. Solicitors must meticulously follow the guidelines for instructing an expert witness, from setting clear instructions to ensuring the expert's report adheres to the prescribed format and their duty to the court. Proactive adherence safeguards the integrity of the evidence, minimises risks, and contributes to the smooth progression of a case. When time is critical, or specific expertise needed, finding an expert quickly and efficiently is paramount. Visit our website to make an expert enquiry today.