The Practice Direction: What Expert Witnesses Must Follow

This article on practice direction expert requirements sets out the formal rules governing asylum expert evidence — CPR Practice Direction 35, UK Upper Tribunal Practice Direction on Expert Evidence (2023), and equivalent frameworks in other jurisdictions. It complements our earlier practice direction article with attention to specific 2023 revisions and enforcement patterns.[1]

Formal compliance with practice directions matters — breaches result in reduced weight or exclusion. Understanding the framework is essential for expert witnesses and instructing solicitors alike.

The Framework

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

Statute and Rules — Civil Evidence Act 1972; CPR 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.

CPR Part 35 Core Rules

Rule 35.3 — expert's overriding duty is to the court. 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

Mandatory content:[3]

1. Details of expert's qualifications.
2. Details of 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.
7. Statement that expert understands duty and has complied.
8. Statement of truth.
9. Signature of expert.

UK Upper Tribunal Practice Direction (2023)

2023 revision adapts CPR framework for immigration/asylum context.[4]

Country expertise emphasis. Country of Origin Information engagement. Country Guidance awareness. Contact details for cross-examination. Availability for hearing attendance. Balanced presentation with contrary evidence.

The Statement of Duty

Model CPR 35.10 declaration:[5]

"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."
Model CPR 35.10 expert declaration

Statement of Truth

Model statement:

"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."
Model statement of truth

Key Case Law

Consequences of Breach

Failure to comply results in:[6]

Reduced weight — most common. Exclusion of evidence — where breach severe. Adverse credibility findings against expert. Costs orders — rare. Professional consequences for regulated experts.

Common Breaches

Missing declaration. Missing statement of truth. Undisclosed instructions. Advocacy tone. Selective evidence. Outdated sources. Opinion outside expertise. Generic content.

US Framework Comparison

US Federal Rules of Evidence 702-706 apply parallel principles. FRE 702 admissibility, Daubert factors, Kumho Tire extension.[7]

Best Practice for Experts

1. Read the Practice Direction before drafting.
2. Include full declaration.
3. Include statement of truth.
4. Disclose all instructions.
5. Cite sources fully.
6. Address CG decisions where applicable.
7. Present contrary evidence.
8. Include CV.
9. Sign and date.
10. Include contact details.

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

Conclusion

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 earlier practice direction article, how to instruct article, and expert witness guide.