CPR 35 Expert Witness Duties Explained for Solicitors

Expert witnesses play a crucial role in UK litigation, providing independent specialist opinions to assist the court. Under Civil Procedure Rules (CPR) Part 35, expert witnesses have specific duties, primarily an overriding obligation to the court, which takes precedence over any instructions from the instructing party. Solicitors must understand and ensure their chosen expert adheres fully to these CPR 35 expert witness duties to ensure the expert's evidence is admissible and credible.

The Overriding Duty to the Court

At the heart of all CPR 35 expert witness duties is the paramount obligation to the court. Rule 35.3 explicitly states that an expert's duty is to help the court on matters within their expertise. This duty overrides any obligation to the person instructing or paying them. This means that an expert witness must always act with independence and impartiality, even if their opinion does not support the instructing party's case.

Solicitors need to make this fundamental principle clear to any expert they instruct from the outset. Failure to acknowledge or adhere to this overriding duty can lead to significant problems, including the expert's evidence being excluded, adverse costs orders, or even professional sanctions against the solicitor or expert. The expert's report and testimony must be objective, based solely on sound professional knowledge and factual evidence, without being influenced by commercial pressures or desired outcomes from the instructing party.

Key CPR 35 Requirements for Expert Reports

CPR Part 35 and its accompanying Practice Direction 35 set out detailed requirements for expert reports. Adherence to these requirements is not merely administrative; it demonstrates the expert's understanding of their duties and the credibility of their evidence. Solicitors must ensure that the expert's report meets all these criteria.

Content and Formalities of an Expert Report

An expert report must be structured logically and contain specific information as stipulated by PD 35.3. Key elements include:

• Expert's Qualifications: A summary of the expert's professional qualifications and experience relevant to the issues in the case.
• Statement of Instructions: Details of the instructions received by the expert, including the identity of the instructing party and the date of the instructions.
• Issues Addressed: Identification of the questions the expert was asked to address and the issues to which the report relates.
• Methodology and Research: A description of any research undertaken by the expert, including site visits, documents reviewed, and tests performed.
• Summary of Facts: A summary of the material facts on which the opinions in the report are based.
• Summary of Opinions: Clear and concise expert opinions on the issues, supported by reasoning.
• Literature and Sources: A list of documents and other materials used or referred to by the expert.
• Declaration of Truth: A statement that the expert understands their duty to the court, that the report contains their true opinion, and that they have complied with PD 35.
• Declaration of Compliance: A statement, signed by the expert, confirming their understanding and adherence to their overriding duty to the court and CPR 35.

Omitting any of these elements can render the report non-compliant and may lead to challenges regarding its admissibility or weight in court. Solicitors should proactively discuss these requirements with the chosen expert and review draft reports carefully to ensure full compliance.

Expert Independence and Impartiality

The principles of independence and impartiality underpin all CPR 35 expert witness duties. An expert must not act as an advocate for any party. Their role is to assist the court, providing objective insights and opinions that remain uninfluenced by outside pressures.

Solicitors should look for experts who demonstrate a clear understanding of this principle. Indicators of an expert's impartiality include their willingness to consider information that may not support the instructing party's case and an ability to articulate areas of uncertainty or disagreement without bias. Experts should also declare any potential conflicts of interest at the earliest opportunity, allowing the instructing solicitor to assess whether the expert can remain impartial.

Consequences of Lack of Independence

If an expert's independence is called into question, the court may:

• Exclude their evidence entirely.
• Give their evidence little or no weight.
• Order the instructing party to pay the costs of the litigation, potentially on an indemnity basis.
• Refer the expert to their professional body for investigation.

These consequences highlight just how critical it is for solicitors to instruct experts who unequivocally embrace their independent duty. When seeking an expert, solicitors may wish to use services like Urgent Expert Witness to find professionals vetted for their understanding of CPR 35 obligations.

Duties Regarding Discussions Between Experts

CPR 35.12 provides for discussions between experts with a view to identifying and narrowing issues, and where possible, reaching agreement. Solicitors have a duty to prepare their expert for these discussions.

The Joint Statement

Following discussions, experts must prepare a joint statement, signed by all participating experts, which sets out:

• Issues on which they agree.
• Issues on which they disagree, providing reasons for their disagreement.
• Any further issues that need to be resolved.

Crucially, the courts have made it clear that experts should contribute to this statement themselves, rather than merely signing a document drafted by legal teams. The joint statement is for the court's benefit and is not binding on the parties unless they expressly agree to be bound. Solicitors must ensure their expert understands that these discussions are not a negotiation but an objective exchange of professional opinions aimed at clarifying and narrowing the issues in contention. Instructing experts who are comfortable collaborating and articulating their positions professionally is vital here. Further guidance can be found on the Judiciary.uk website.

Expert's Duty of Candour and Revision of Opinion

An expert's duty to the court continuous throughout the litigation process. This means that if an expert changes their opinion on a material matter, they must inform all parties, and the court, immediately. CPR 35.10(4) states that if an expert's view changes, the report must be amended, and the changes explained. This demonstrates the expert's ongoing commitment to professional integrity and their overriding duty to help the court.

Solicitors must ensure their experts are aware of this ongoing obligation. It is not uncommon for new evidence to emerge or for an expert to re-evaluate their initial assessment based on further information. Such changes, while potentially unwelcome to an instructing party, are a mark of an expert's independence and dedication to their court duty. Instructing experts who understand this duty of candour prevents last-minute surprises and upholds the integrity of the expert evidence.

Practical Implications for Solicitors

Understanding CPR 35 expert witness duties is not merely academic for solicitors; it has direct practical implications for case management and strategy. Proper instruction and management of expert witnesses are critical for successful litigation.

Solicitors should take the following steps:

1. Careful Selection: Choose experts not only for their technical expertise but also for their understanding of CPR 35 duties and their ability to remain impartial. Services that specialise in sourcing experts, such as those listed on our /blog might be helpful.
2. Clear Instructions: Provide clear, precise, and CPR-compliant instructions, including a specific reminder of the expert's overriding duty to the court. Avoid language that could be seen as encouraging a partisan approach.
3. Reviewing Draft Reports: Thoroughly review draft reports for compliance with PD 35 and to ensure clarity, logical reasoning, and absence of advocacy.
4. Managing Discussions: Prepare experts for joint discussions, ensuring they understand the purpose and their duty to prepare a truly joint statement.
5. Ongoing Communication: Maintain open communication with the expert, ensuring they report any changes in opinion promptly.

Adherence to CPR 35 requirements ensures the expert evidence is robust, admissible, and carries weight with the court, ultimately serving the interests of justice.

FAQ

What is an expert witness's primary duty under CPR 35?

An expert witness's primary duty under CPR 35 is to assist the court on matters within their expertise. This overriding duty takes precedence over any obligation to the party instructing or paying them, ensuring impartiality.

Can a solicitor influence an expert's opinion?

No, a solicitor must not seek to influence an expert's independent opinion. While they can provide instructions and context, the expert's ultimate opinion must be their own, formed objectively based on their expertise and the facts.

What happens if an expert's report doesn't comply with CPR 35?

If an expert's report does not comply with CPR 35, the court may refuse to allow the party to rely on the expert's evidence. This can lead to delays, increased costs, and weaken a party's case significantly.

Do experts always have to agree during discussions?

No, experts are not required to agree during discussions. Their duty is to identify and narrow issues and explain any disagreements and the reasons for them in a joint statement, to assist the court.

What should an expert do if they change their mind?

If an expert changes their opinion on a material matter after submitting their report, they must immediately inform all parties and the court, and provide a supplementary report explaining the changes and the reasons for them.

Adhering to CPR 35 expert witness duties is fundamental for the integrity of legal proceedings, ensuring justice is served based on impartial, credible evidence. Solicitors must therefore appreciate these duties, selecting and managing experts who wholeheartedly embrace them. For urgent assistance in finding a qualified expert witness who fully understands their CPR 35 obligations, do not hesitate to submit a confidential request today.