THE COURT CANNOT COMPEL A PARTY TO CALL A WITNESS: “PARTY AUTONOMY IS PARAMOUNT”
In QX v Secretary of State for the Home Department [2022] EWCA Civ 1541 (22 November 2022) the Court of Appeal held that the courts have no power to compel a party to call a witness.

“The starting proposition must be this: in civil litigation, a court has no general power to order one party to call, as a witness on the substantive issues, a person whom that party does not wish to call. Party autonomy is paramount:”
THE CASE
The applicant brought an appeal in a case relating to the provisions of the Counter-Terrorism and Security Act 2015. As part of the orders the court made below it was ordered that the respondent file a witness statement. There was a cross-appeal against that decision. The applicant’s appeal was allowed in part. The judgment of Lord Justice Coulson dealt with the cross-appeal. The cross-appeal was allowed.
THE JUDGMENT ON THE WITNESS STATEMENT
“The Defendant shall file and serve a witness statement from a person able to speak to the national security case. The maker of the statement should be available for cross-examination at the final hearing of the Claimant’s review.”
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On behalf of SSHD, Mr Tam KC submitted that this order should be quashed. He put his submission in two ways. First, he said that the judge had no power to make an order requiring one party to file and serve a witness statement from X, in circumstances where that party did not wish to call X as a witness. Secondly he said that, if the court did have the power, it should not have been exercised in this way in this case.
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The starting proposition must be this: in civil litigation, a court has no general power to order one party to call, as a witness on the substantive issues, a person whom that party does not wish to call. Party autonomy is paramount: see Zuckerman on Civil Procedure: Principles of Practice, 4th Edn., at 11.11. As Professor Zuckerman goes on to note at 11.12: “parties to a dispute are autonomous in procedure. They are free to choose whether to litigate, what to litigate and what evidence to call in support of their respective allegations”. They are free to choose which evidence to include and which evidence to leave out. That is a decision with which the court cannot interfere, even if the evidence in question is regarded as significant: see Zuckerman at [11.15].
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Party autonomy extends to all aspects of civil litigation: for example, there is no requirement for a claimant to plead all the claims he could arguably advance (see Dyson LJ in Khiaban v Beard [2003] EWCA Civ 358). And in Air Canada v Secretary of State for Trade [1983] 2 AC 394, the House of Lords accepted that the principle of party autonomy meant that material facts may be withheld from the scrutiny of the court. Lord Fraser said:
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“In an adversarial system such as exists in the United Kingdom, a party is free to withhold information that would help his case if he wishes-perhaps for reasons of delicacy or personal privacy. He cannot be compelled to disclose it against his will” (at 434D)
This and related passages in Air Canada have recently been cited with approval by the Supreme Court in Sainsbury’s Supermarkets Ltd v Mastercard Inc [2020] UKSC 24 at [242]. I acknowledge that somewhat different principles may apply to public authorities when they defend applications for judicial review.
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If the other side considers that the evidence of X is crucial, it can issue a witness summons under CPR Part 34 and call X itself. Of course, that is not always a safe course because, in civil litigation, the party calling X cannot cross-examine him or her; his evidence would have to be adduced by way of examination-in-chief in the conventional way. It is for that reason that a party in a similar position to QX in this case does not regularly use Part 34 and will instead submit that, without the evidence of X, the other side’s case must fail.
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An entirely different situation arises if a party has provided a witness statement from X but does not wish to tender him or her for cross-examination. In those circumstances, if the court considers that the evidence of X is important and cannot be dealt with satisfactorily other than by way of oral evidence, then (even in judicial review proceedings) the court will order that witness to be tendered for cross-examination: see R(PG) v London Borough of Ealing and Ors [2002] EWHC 250 (Admin) at [20]. That is, of course, a very different thing from ordering X to provide a witness statement in the first place.
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In support of the suggestion that the court has the power to order a party to call a witness, Mr Squires KC relied on the decision of Thirlwall J (as she then was) in XYZ v Various [2013] EWHC 3643 (QB); [2014] 2 Costs LO 197. In that case, Thirlwall J exercised her power under CPR 3.1(2)(m) – that the court may “take any…step or make any other order…for the purposes of managing the case and furthering the overriding objective…” – to order the lead defendant in group litigation to explain its financial position to the claimants. Thirlwall J accepted that the defendant’s financial position was not a matter in dispute in the proceedings, but she said that the financial position of the lead defendant impacted significantly upon the directions and timetable leading up to the trial, and that the order that she proposed to make was necessary for the purpose of managing the case and furthering the overriding objective.
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Mr Squires suggested that XYZ justified the order that the judge made here. I disagree. XYZ was a very different case on its facts, concerned as it was with the age-old problem of a defendant who does not wish to disclose its financial (or insurance) position, usually for tactical reasons. The application was only successful in XYZ because the defendant’s financial position had a significant impact upon the management of the case up to the trial.
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In the present case, the risk that QX presents to national security is a critical substantive issue between the parties. It has nothing to do with case management or furthering the overriding objective. Rule 3.1(2)(m) was therefore irrelevant, because the order made by the judge in this case was not required for case management purposes. It went to a substantive issue between the parties. On the face of it therefore, the judge’s decision was not supported by XYZ.
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It is also worth exploring briefly why the judge in the present case made what, on the face of it, was the surprising order requiring SSHD to tender a witness on a particular subject. The root of the problem can, I think, be found in the nature of the material presently put forward by SSHD in this case which, Mr Tam said, was common in national security cases. Pursuant to CPR Part 88 (the part of the CPR brought in and concerned with proceedings under the 2015 Act), “the court may receive evidence that would not, but for this rule, be admissible in a court of law” (see r.88.25(4)). Mr Tam’s proposition that this may include material other than conventional witness statements derives some limited support from the wording of r.88.12(c)(vii) and r.88.14(2).
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In the present case, what the SSHD relies on as evidence in respect of national security matters are two “statements”. These are unsigned and undated. They address the risk QX presents to national security. Such statements would not be evidence in the normal way because they are unattributed. They could, however, be admissible under r.88.25(4), but only if the judge expressly agreed to “receive” them as such. I do not agree with Mr Tam that the rule somehow automatically allows such material as evidence in a TEO review. What is admissible or not, even under the particular regime of a TEO review, must always be a matter for the judge.
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Here the judge permitted reliance on the two statements, even though they were unattributed: see [64] of her judgment. She then went on to decide that the statements were not, or may not be, enough: see [80]-[86]. That last paragraph concludes with her order as to the filing and service of a witness statement.
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In my view, the judge considered the issues in the wrong order. She had first to decide whether the unattributed statements were admissible in that form pursuant to r.88.25(4). If she concluded that they were, then that was the end of it: they could be relied on by the SSHD without more. Of course, if the lack of attribution or other deficiencies stemming from the generalised nature of the statements created a difficulty for the SSHD in the review itself, that was a matter for the SSHD.
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If the judge decided that the statements were not admissible in that form, then she had a choice. On the one hand, she could simply have ruled the statements out of account altogether. On the other, by way of proactive case-management, the judge could have suggested to the SSHD that they would be admissible if they were the subject of a short witness statement, with that witness then being tendered for cross-examination. It would then have been for the SSHD to decide whether to accept or reject that suggestion. The judge could not order it, but a strongly-worded suggestion might have achieved the same result.
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It seems to me that following that sequence is logical and fair. It properly protects both the SSHD and the appellant, and it allows the judge to remain as the neutral arbiter of the material each side chose to rely on. Simply ordering the SSHD to call a witness, whether she wanted to or not, was beyond the judge’s powers. I would therefore allow the cross-appeal.
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