The Practice Direction: What Expert Witnesses Must Follow

The UK Upper Tribunal Practice Direction on Expert Evidence (2023 revision) and CPR Practice Direction 35 set out what is required of expert witnesses in asylum cases. These directions define the formal framework — declarations, format, disclosure of instructions, duty to the court — that experts must comply with. Breaches result in reduced weight or exclusion of evidence.[1]

The Practice Direction operates alongside CPR Part 35 (the rules themselves) and case law. Together they constitute the binding framework for expert evidence in UK asylum tribunals. Equivalent frameworks operate in US Federal Rules of Evidence 702-706, Canadian IRB Rules, and EU national procedural rules.

The Framework

The UK expert evidence framework operates at three levels.[2]

Statute and Rules — Civil Evidence Act 1972; Civil Procedure Rules Part 35. Practice Directions — CPR PD 35; UK Upper Tribunal Practice Direction on Expert Evidence (2023). Case law — Mibanga v SSHD [2005] EWCA Civ 367, SA (Somalia) [2006] EWCA Civ 1302, and others.

CPR Part 35 Core Rules

CPR Part 35 establishes the substantive rules. Key provisions include the following.[3]

Rule 35.3 — expert's overriding duty is to the court, not to the party. Rule 35.4 — court may restrict expert evidence. Rule 35.10 — report must contain statement of duties and be verified by statement of truth. Rule 35.12 — court may direct discussions between experts. Rule 35.13 — expert may not give oral evidence unless report served.

CPR PD 35 Content Requirements

CPR Practice Direction 35 paragraph 3.2 sets out the mandatory content of expert reports. Elements include the following.[4]

1. Details of expert's qualifications.
2. Details of any literature relied on.
3. Statement setting out substance of instructions.
4. Facts and instructions given to expert that are material.
5. Range of opinion where applicable.
6. Summary of conclusions reached.
7. Statement that the expert understands their duty and has complied with it.
8. Statement of truth.
9. Signature of expert.

UK Upper Tribunal Practice Direction (2023)

The UK Upper Tribunal (Immigration and Asylum Chamber) Practice Direction on Expert Evidence (2023 revision) adapts these requirements for the asylum context. Distinctive elements include:[5]

Country expertise emphasis — specific country knowledge required. Country of Origin Information (COI) — reports should engage with authoritative COI. Country Guidance (CG) awareness — reports must address applicable CG decisions. Contact details for cross-examination. Availability for attendance at hearing. Balanced presentation — including contrary evidence.

The Statement of Duty (Declaration)

The declaration required by CPR 35.10 must include specific elements. Model wording:[6]

"I understand that my duty is to help the court on matters within my expertise. This duty overrides any obligation to the person from whom I have received instructions or by whom I am paid. I confirm that I have complied with and will continue to comply with that duty. I have set out in my report what I understand from those instructing me to be the questions in respect of which my opinion as an expert is required. I have done my best in preparing this report to be accurate and complete. I have mentioned all matters which I regard as relevant to the opinions I have expressed."
Model CPR 35.10 expert declaration

Statement of Truth

The statement of truth verifies factual accuracy. Model wording:

"I confirm that I have made clear which facts and matters referred to in this report are within my own knowledge and which are not. Those that are within my own knowledge I confirm to be true. The opinions I have expressed represent my true and complete professional opinions on the matters to which they refer."
Model statement of truth for expert report

Key Case Law

Consequences of Breach

Failure to comply with the Practice Direction can result in the following.[7]

Reduced weight — most common consequence. Exclusion of evidence — where breach is severe. Adverse credibility findings — against the expert. Costs orders — in rare cases. Professional consequences — for experts subject to professional regulation.

Common Breaches

Missing declaration — no CPR 35.10 statement. Missing statement of truth. Undisclosed instructions — instructions from party not disclosed. Advocacy tone — reads as party submission. Selective evidence — contrary evidence not addressed. Outdated sources — reliance on stale country information. Opinion outside expertise — country expert opining on medical matters. Generic content — no application to specific applicant.

US Framework Comparison

US Federal Rules of Evidence 702-706 apply parallel principles. FRE 702 requires expert testimony be based on sufficient facts, reliable principles, and reliably applied. Daubert v Merrell Dow 509 US 579 (1993) and Kumho Tire Co v Carmichael 526 US 137 (1999) establish the reliability framework.[8]

Canadian Framework Comparison

Canadian IRB Rules and IRPR sections 174-175 apply parallel principles. IRB Chairperson Guidelines on gender, LGBT, and other categories supplement.

Best Practice for Experts

1. Read the Practice Direction before drafting.
2. Include full declaration — CPR 35.10.
3. Include statement of truth.
4. Disclose all instructions.
5. Cite sources fully — bibliography.
6. Address CG decisions where applicable.
7. Present contrary evidence — engage rather than ignore.
8. Include qualifications — CV.
9. Sign and date.
10. Include contact details for cross-examination.

The Practice Direction is not bureaucratic ritual — it is the framework that ensures expert evidence commands weight. Compliance signals seriousness; breach signals lack of professionalism. The rules are simple; following them is not optional for serious expert work.
UK Upper Tribunal Practice Direction on Expert Evidence (2023)

Conclusion

The UK practice direction expert requirements — CPR PD 35 and UK Upper Tribunal Practice Direction on Expert Evidence (2023) — set the framework experts must follow. Ten-plus mandatory content elements. Declaration and statement of truth required. Case law confirms tribunals must engage with expert evidence. Breaches result in reduced weight or exclusion. See our companion expert witness guide, expert report contents article, and how to instruct article.