Expert Witness Journal Issue 68 August 2026 - Flipbook - Page 8
What should an expert witness
expect from a court-compliant
letter of instruction?
by Bond Solon.
A Court of Protection case that was heard last
month provides invaluable guidance to all expert
witnesses about what a letter of instruction that is
compliant with best practices should contain
What should a letter of
instruction contain?
Outlining the requirements of the letter of
instruction itself, Justice Theis warned against
“lengthy and unwieldy recitations of the background
facts and procedural history” or “detailed
descriptions of previous case law”.
Bristol City Council v CC & Ors [2026] EWCOP 19
concerned the capacity of CC, a 23-year-old male with
a complex social and mental health background.
She said it should be “focussed and adapted to the
facts of the particular case” and pointed to AMDC
v AG and CI [2020] EWCOP 58 [28 (b)] in which Mr
Justice Poole said the letter of instruction should
“identify the decisions under consideration, the
relevant information for each decision, the need to
consider the diagnostic and functional elements of
capacity, and the causal relationship between any
impairment and the inability to decide”.
The judge, Mrs Justice Theis DBE, was critical of the
way in which documentation relevant to the case was
passed to the expert witness.
She said:
“
Those willing to give expert evidence in cases in the
Court of Protection are an invaluable resource to
assist the parties and the court reach decisions in
these di昀케cult cases. The parties and the court need
to ensure that all necessary steps are taken to enable
them to undertake that important role.”
Mrs Justice Theis advised experts that if they are
“unsure what decisions they are being asked to
consider, what the relevant information is in respect
to those decisions, or any other matter relevant
to the making of their report, they should ask for
clari昀椀cation”.
The Judge invited the parties to produce an agreed
note on the instruction of experts in the Court of
Protection, which they duly did.
When and how should an expert witness
be instructed?
She then outlined the key components that an
expert witness should expect to see in their letter of
instruction:
Rule 15 of the Court of Protection Rules 2017
provides guidelines on how experts should be
instructed and reminds parties that expert evidence
should only be requested when it is “necessary” for
the court to reach a resolution. Similar instructions
can be found in the equivalent procedural rules for
civil, criminal and family cases.
Justice Theis said a draft letter of instruction to the
expert should ideally be signed o昀昀 by the court. If
that is not possible then the court should have sight
of the questions the expert is being posed.
EXPERT WITNESS JOURNAL
6
•
Statement of facts and list of materials. A brief
“neutral” statement of the facts of the case, with
a list of the materials the expert is expected to
assess before reaching an opinion.
•
Core legal framework. As this case was a Court
of Protection hearing, the judge suggested
including the core legal principles of the MCA
2005, or a summary of those that are relevant
to the case. Similar legal frameworks should be
included for hearings in the criminal, civil, or
family courts or specialist tribunals.
AUGUST 2026
