The Practice Direction: What Expert Witnesses Must Follow

Last updated: 5 October 2026

Photo: United Nations, - Paul VanDerWerf

Expert witnesses in UK asylum and immigration proceedings are bound by specific procedural requirements. The leading document is the UK Upper Tribunal (Immigration and Asylum Chamber) Practice Direction expert witnesses must follow — the 2018 Practice Direction on Country Guidance and Expert Evidence. Together with Civil Procedure Rules Part 35 and the Senior President of Tribunals' Practice Directions, this framework sets the standards expert witnesses must meet for their evidence to be admitted and weighted. This asylum guide sets out what the Practice Direction requires.[1]

The evidence base draws on the 2018 UK Upper Tribunal Practice Direction, CPR Part 35, the Civil Procedure (Amendment) Rules 2013, the Tribunal Procedure (Upper Tribunal) Rules 2008, the leading case The Ikarian Reefer [1993] 2 Lloyd's Rep 68, and ILPA best practice guidance.

Background: The Regulatory Framework

Expert evidence in UK immigration proceedings sits within a layered regulatory framework. Civil Procedure Rules Part 35 governs expert evidence in civil proceedings generally. The Tribunal Procedure Rules apply CPR principles to immigration tribunals. The 2018 Senior President of Tribunals' Practice Direction on Country Guidance and Expert Evidence provides immigration-specific guidance. Common-law principles, particularly The Ikarian Reefer, set out the underlying duties.[2]

The Seven Core Duties

From CPR Part 35, the Practice Direction, and Ikarian Reefer, seven core duties for expert witnesses can be identified. Compliance with all seven is necessary for evidence to carry full weight.[3]

1. The Independence Duty

CPR Part 35.3 is unambiguous. The expert's duty is to "help the court on matters within their expertise" and this duty "overrides any obligation to the person from whom experts have received instructions or by whom they are paid." This is the foundational duty. An expert who acts as an advocate for the instructing party violates the duty and undermines the evidence's weight.[4]

2. The Objectivity Duty

The first Ikarian Reefer principle requires that expert evidence be "the independent product of the expert uninfluenced as to form or content by the exigencies of litigation." This duty bites particularly hard when the expert is asked to comment on close questions where party advantage may pull. Compliance requires the expert to assess the evidence on its merits, not on what serves the instructing party.[5]

3. Addressing All Material

CPR Part 35 Practice Direction paragraph 3.2 requires that an expert report "describe any examinations, measurements, tests or experiments which the expert has used for the report; give the qualifications of the person who carried out any such examination, measurement, test or experiment; and give details of any literature or other material on which the expert has relied in making the report." Importantly, this includes material that detracts from the conclusions. An expert who omits adverse country information undermines their own credibility.[6]

4. Staying Within Expertise

The fourth Ikarian Reefer principle requires that "an expert witness should make it clear when a particular question or issue falls outside [their] expertise." This includes avoiding opinions on legal questions reserved to the tribunal. An expert may comment on factual country conditions but should not opine that "the applicant is a refugee within the meaning of the Convention" — that is for the judge.[7]

5. Reasoned Conclusions

CPR Practice Direction 35 paragraph 3.3 requires that "where an expert is given the same information as the other party and the conclusions they reach differ from those of the other expert, the basis for the disagreement should be made clear in the report." More broadly, every conclusion in a report should be supported by transparent reasoning — the expert's methodology, the sources consulted, and the analytical steps that lead to the conclusion. See our companion article on return risk methodology.[8]

6. Avoiding Advocacy

The second Ikarian Reefer principle requires that "an expert witness should provide independent assistance to the court by way of objective unbiased opinion in relation to matters within his expertise." Advocacy language, partisanship, and selective emphasis all violate this duty. Reports that read as if drafted by the applicant's legal team rather than by an independent expert are routinely discounted.[9]

7. Required Declarations

CPR Practice Direction 35 paragraph 3.3 requires specific declarations. A standard expert report should include:

• Statement of truth — "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."
• Statement of understanding — confirming the expert understands the duty to the court overrides any other obligation.
• Statement of compliance — confirming compliance with CPR Part 35 and the relevant Practice Direction.

Where the expert report is properly prepared, with a clear methodology, transparent sourcing, balanced engagement with the evidence, and proper declarations, it provides decisive assistance to the tribunal. Reports that fall short of the Practice Direction's requirements are heavily discounted, regardless of the expert's qualifications.
UK Upper Tribunal (IAC), Practice Direction on Country Guidance and Expert Evidence (2018)

Consequences of Failure

Reports that fail to comply with the Practice Direction face several consequences.[10]

• Reduced weight — tribunals routinely discount non-compliant reports.
• Exclusion — in extreme cases, evidence excluded entirely.
• Adverse credibility findings — reflecting on the case as a whole.
• Loss of expert standing — tribunals share criticisms across cases.
• Professional consequences — for the expert and for the instructing legal team.

For Instructing Lawyers

Lawyers instructing expert witnesses should ensure compliance with the Practice Direction. Practical steps include the following.[11]

1. Reference the Practice Direction in the letter of instruction.
2. Confirm the expert's familiarity with CPR Part 35 and the immigration-specific Practice Direction.
3. Provide complete documents including unfavourable material.
4. Review the report for compliance with declarations and required disclosures.
5. Address methodology explicitly in the report structure.
6. Ensure the expert's CV demonstrates relevant expertise.

Conclusion

The 2018 UK Upper Tribunal Practice Direction on Country Guidance and Expert Evidence, together with CPR Part 35 and the underlying Ikarian Reefer principles, sets the framework for expert witnesses in UK immigration proceedings. Seven core duties — independence, objectivity, addressing all material, staying within expertise, reasoned conclusions, avoiding advocacy, and required declarations — must be met.

For experts, compliance with the Practice Direction is the foundation of giving evidence that carries weight. For instructing lawyers, ensuring compliance is part of effective case preparation. See our wider Expert Witness Hub series: complete guide, how to instruct, report structure, and jurisdictional differences.