The Chief Constable of Sussex Police v XGY: Two doors shut, but others stay open

Introduction

On 8 October 2025, Lady Carr, Dame Victoria Sharp P and Lord Justice Coulson handed down judgment in The Chief Constable of Sussex Police and the CPS v XGY and the Bar Council [2025] EWCA Civ 1230, rejecting a claimant’s claims against the Crown Prosecution Service (‘CPS’) and the Chief Constable (‘the police’).  Those claims had involved challenge to the ‘core immunity’ – immunity from suit in respect of things said and done by advocates in court.

In this article, Chris Greenwood and Faye Metcalfe recap the background and inroads made into the core immunity thus far, consider what the decision in Chief Constable v XGY means for lawyers and expert witnesses, and explore its potential consequences on the routes by which litigants might still seek to attack lawyers and expert witnesses for conduct of and statements made in court hearings.

Immunity: a brief history

The core immunity, where it applies, acts as an absolute bar to persons taking part in legal proceedings (judge, counsel, witness, juror or other party) being sued for almost anything done or not done in the course of conducting a case in court.

The reasons underpinning the immunity are both policy driven – advocates and witnesses must be able to speak freely in court without fear of being sued for what they say, and advocates must also argue their client’s case as best they permissibly can – but also practical; as the Court of Appeal held nearly 150 years ago: “it is the fear that if the rule were otherwise, numerous actions would be brought against persons who were merely discharging their duty.”[i]  In simple terms, a ‘floodgates’ argument.

Given that the doctrine of immunity necessarily conflicts with the principle that every wrong should have a remedy, the test for extending the immunity beyond its core applicability to statements made in the courtroom is strict: it must be necessary for the proper administration of justice:

• Of importance to advocates, the immunity has been extended beyond statements made in court, but only “where the particular work is so intimately connected with the conduct of the cause in court that it can fairly said to be a preliminary decision affecting the way that cause of action is to be conducted when it comes to a hearing”: Saif Ali and Anor v Sydney Mitchell & Co [1980] AC 198, 215D.
• In Watson v M’Ewan [1905] AC 480, the core immunity afforded to witnesses giving evidence in court was extended to include statements made by witnesses outside of court, but only where such statements were made with a view to giving evidence. The same extension was applied in CLG v Chief Constable of Merseyside Police [2015] EWCA Civ 836, covering claims arising out of the disclosure of a victim’s address in a police officer’s statement supporting an application for arrest warrants.
• In Taylor v Director of the Serious Fraud Office [1999] 2 AC 177, the House of Lords further extended the immunity to include statements made out of court by potential witnesses (as well as statements made by investigators), but again, only where they were made with a view to potentially giving evidence.

And in some cases, attempts to extend the principle have strayed too far outside the courtroom:

• In both Darker v Chief Constable of the West Midlands [2001] 1 AC 435 and Singh v Reading Borough Council [2013] EWCA Civ 909, the immunity was held not to cover claims that the defendants had conspired to fabricate false evidence and pressurised a witness to include inaccurate witness evidence in her statement; the defendants’ actions in fabricating and procuring the evidence were held to have been divorced from the evidence/statements that resulted.
• The immunity also did not apply in Daniels, where a claim for misfeasance in public office arising from to the concealment/withholding of evidence was held not to be founded on the content of any statement, but rather the way in which the disclosure exercise was performed.

There are also some types of claims to which, even inside the courtroom, the core immunity does not apply at all:

• In Arthur JS Hall & Co v Simons [2002] 1 AC 615, the House of Lords held that the public interest in the administration of justice no longer required that advocates enjoy immunity from suit for negligence alleged by former clients in the conduct of civil proceedings. The principles of res judicata, issue estoppel and abuse of process were held to provide adequate protection against re-litigation, and the Court’s power under CPR r.24.2 would restrict the ability of clients to bring unmeritorious or vexatious claims against advocates absent the immunity.
• Jones v Kaney [2011] 2 AC 398 built upon Hall, abolishing the expert witness’s immunity for claims in negligence brought by their clients.
• Suits of malicious prosecution, malicious initiation of criminal proceedings, prosecution for perjury and proceedings for contempt of court have also long been held not to be covered by the immunity (Daniels v Chief Constable of South Wales [2015] EWCA Civ 680).

Accordingly, while the starting point remains that the immunity covers any cause of action brought against the relevant party for written or spoken statements made in court, it is a point from which very substantial departures have already been made.

Chief Constable v XGY

The claimant had been in a relationship with her former partner, DYP, who was the accused in the underlying criminal proceedings.  Following the end of that relationship, the claimant moved addresses two times, relocating to an address in Hampshire, which she told the police about and asked to be kept confidential.  Having initially accused the defendant of various forms of assault and threats to kill, at the same time as providing the address, she also told the police that during their relationship, DYP had raped her.

The police arrested DYP, and in preparing a file for DYP’s bail hearing, passed the claimant’s address to the CPS without marking it as confidential.  During the bail hearing, the advocate for the CPS sought to include a condition of bail preventing DYP from going to the address and in doing so informed DYP of the address.

The claimant brought claims for damages against the Chief Constable and CPS pursuant to the Human Rights Act 1988 (by reference to Articles 2, 3 and 8 of the Convention), for breach of the Data Protection Act 2018, and for breach of confidence and misuse of and/or unjustified disclosure of private information.

Both defendants applied to strike out the claims against them.[ii] The CPS contended they were immune from suit since the claims related to something said by an advocate in court, and the police argued, amongst other things, that the core immunity extended to their provision of the address to the CPS.

Judgment of HHJ Brownhill

HHJ Brownhill struck out the claims against both defendants, holding that (1) although any new extension to an immunity required detailed examination, the law did not require cases falling within an already established immunity to be subjected to a trial into the relevant public policy considerations; and (2) Hall had only removed an advocate’s immunity in relation to negligence claims brought by the advocate’s own client, not any other immunity.

HHJ Brownhill concluded that since the disclosure of the claimant’s address fell squarely within the established advocate immunity (statements made in court by an advocate) that action must fail, and that police’s inclusion of the address in the CPS file was similar to the file note in Taylor v DSFO, such that it fell within an established extended immunity.[iii]

Judgment of Ritchie J

Ritchie J allowed the claimant’s appeal.

Ritchie J considered that outside of certain ‘core’ categories of immunity (which he labelled “Witness Immunity at Court “Judges Immunity at Court” and “parts of Advocates Immunity at Court relating to the evidence in the case”), “the appellate Courts have arguably stated the correct approach to claimed immunities… is to grant or permit them “grudgingly”, because they undermine the key principle that every wrong should have an appropriate redress in law”.  Accordingly, where there were relevant factual issues potentially making the claimed immunity “unsettled” in scope or justification, “the justification should be analysed on the necessary evidence to see if it makes immunity necessary in the public interest”.

Ritchie J’s rationale was that in the last 25 years there had been a move away from “absolutism” towards a “justification approach”: a “careful consideration of whether the facts of each case actually do fit with the claimed “immunity” by reference to whether the long-established justifications for the immunity apply”.

So, Ritchie J held, where a defendant relied on the immunity but the claimant asserted it was unjustified or the claim fell outside of its scope on the facts, the court should conduct a “balancing exercise to be carried out to determine whether the way the function was performed so undermined the justifications for the claimed immunity” that it should not be granted.

Adopting this approach, Ritchie J held that:

1. The police were not covered by the scope of ‘Witness Immunity at Court’, because the address was not evidence in relation to the criminal case being investigated. And while they may have been covered by  ‘Legal Proceedings Immunity before Court’, this was not a ‘core immunity’ and so the Court should have considered the justifications for granting the immunity, and it was also arguable that the function performed was “administrative” and so fell outside the scope of the immunity altogether.
2. As to the CPS, it was arguable that the core part of the ‘Advocates’ Immunity at Court’ related to “witness evidence in the case, not to extraneous or peripheral or administrative matters”, so that again, a balancing exercise between public policy concerns should have been carried out by HHJ Brownhill.

The Court of Appeal’s decision

On appeal by the Chief Constable and CPS, the Court of Appeal held that HHJ Brownhill was right to conclude that the claims against the CPS had to fail.  Although the claimant’s address should not have been disclosed, “the words of the CPS advocate were spoken indubitably “in the course of court proceedings” and so covered by the core immunity”.

In doing so, the Court of Appeal rejected Ritchie J’s “justificationism” approach.  Instead, the Court held:

1. Where the facts fall within an existing immunity (rather than requiring a new extension), the application of the immunity does not need to be justified on a ‘case-by-case basis’.

“It is wrong to elide the requirement to justify categories of immunity with the requirement to justify the actions of a person on the facts of every case. If a claim falls within the scope of the core immunity or its established extensions, the claim must be struck out. To be effective, foreseeability is essential if those involved in the administration of justice are to speak freely. The approach of “justificationism” fundamentally undermines the public policy underlying the existence of the immunity.”

2. It is only when a new extension is sought that the necessity of the immunity has to be justified.
3. The decisions in Hall and Jones did not exemplify a move “away from absolutism” towards “justificationism”. Instead, Hall involved a specific challenge to an existing immunity based on policy (namely that counsel should be immune from suit by their own clients in negligence), and Jones focussed exclusively on whether an expert witness’ immunity should continue to extend to claims in negligence brought by their own client.
4. Contrary to Ritchie J’s interpretation of Darker, “The core immunity is not limited to evidential matters. It is far wider in scope. The immunity attaches to statements (said or written) made in court. Whether or not a statement is related to evidence, is a limiting factor only in the extension of the core immunity to statements made by potential witnesses outside of court – such statements are only within the scope of the extension if they are made with a view to giving evidence.” Accordingly, the claimant’s address did not need to be related to the alleged offences for its disclosure to be covered by the immunity.
5. The core immunity and its extensions apply to bail hearings, such hearings being “an integral part of proceedings in the criminal court”.

The Court of Appeal further held that the police were covered by the extended immunity identified in Watson, Taylor, and CLG.  The police’s preparation of the bail hearing file fell within the process of criminal investigation and administration of justice.  Accordingly, Ritchie J was wrong to impose the ‘evidential’ requirement that he did.

The Court of Appeal also addressed the question of what type of claims the immunity covers, reiterating that save for narrow exceptions – including claims for negligence by the party’s own client – the immunity “cannot be outflanked by other claims, no matter how they are formulated.”

Attacks on proceedings: does Chief Constable v XGY redraw the lines of defence?

The Court of Appeal’s decision makes two things clear:

1. Where a claim falls within an established immunity category, it is not open to the claimant to simply invite the Court to consider whether the immunity is justified on the facts of the case.
2. The Court will not distinguish between ‘administrative’ or ‘evidential’ statements made in court; the test is simply whether the words were written or “spoken “in the ordinary course of court proceedings”.

But other doors remain ajar:

• The Court noted that “Public policy can change over time and be re-evaluated”. Hall is a paradigm example; thirty years earlier, in Rondel v Worsley [1969] 1 AC 191, the House of Lords considered the very same question concerning negligence claims against advocates by their own clients, but gave the opposite answer.  Does this mean that a claimant who raises a ‘policy argument’ will avoid having their claim struck out?  Or are first instance judges tasked with deciding whether such arguments stand a real prospect of success?  And how often will the higher Courts be willing to reevaluate previous policy decisions?
• Professional negligence claims by clients against advocates and experts are here to stay. But what if, in Chief Constable v XYG, the claimant had informed the CPS advocate at the hearing that she was considering not giving evidence at trial, but the advocate had promised not to reveal her address?  This might arguably be a voluntary assumption of responsibility, i.e. a relationship ‘akin to contract’; would an arguable claim therefore lie?

The Court of Appeal also made clear their decision did not concern the well-established exceptions to the immunity, nor does it impact claims in respect of actions outside of (and not sufficiently connected to) the courtroom.  And in recent years there has been no shortage of litigants making use of them:

• Committal proceedings for contempt of court: Committal proceedings continue to represent a degree of risk to witnesses in proceedings, including expert witnesses. However, some of that risk is mitigated by the permission filter at CPR r.81.3.  In Frain v Reeves [2023] EWHC 73 (Ch), the Court emphasised the need to exercise great caution before granting permission to bring committal proceedings, to assess the public interest in bringing such proceedings on a case-by-case basis, and to “guard against the risk of allowing vindictive litigants to use committal proceedings to harass persons against whom they have a grievance”.
• Malicious prosecution: In Willers v Joyce [2018] AC 799, the Supreme Court held that the tort of malicious prosecution included the prosecution of civil proceedings, and that witness immunity did not bar malicious prosecution claims, because they were not brought in respect of the evidence given in court, but rather in respect of the malicious abuse of process.
• Unlawful means conspiracy claims: This tort has proved a popular means by which litigants have sought to attack proceedings notwithstanding the immunity. Unlike the first two examples, it is fallible to the immunity.  However, litigants can still argue that their claims do not arise from the content of statements made in court, but the manner in which it was procured, as the successful claimants did in Darker, Singh and Daniels.
• Causing loss by unlawful means: This tort is similarly fallible to the immunity, but that does not assist a defendant who never issued proceedings at all. In Vanquis Bank Ltd v TMS Legal Ltd [2025] EWHC 1599 (KB), the Court declined to strike out or grant summary judgment against a bank’s claim that the defendant solicitors had caused it loss by unlawful means by making unmeritorious financial mis-selling complaints against it to the Financial Ombudsman Service.
• Claims for misuse of private information: Following Chief Constable v XGY there is no doubt that such claims fall within the core immunity, but as with unlawful means conspiracy claims, this will not assist a defendant who has misused such information in the process of producing their evidence; one example may be Kul v DWF LLP [2025] EWHC 1284 (KB), where the defendant did not seek to rely on the immunity, but in any event succeeded on other grounds.

Conclusion

The Court of Appeal’s rejection of “justificationism” whenever the immunity defence is raised enhances foreseeability, and will be welcomed by those who practice in the courtrooms of England and Wales.  The decision also provides helpful clarity that the statement complained of need not relate to the substance of the index claim in order for the immunity to apply.  But potential exposure for lawyers and expert witnesses to claims by opponents in litigation (and other dispute resolution mechanisms) remains; the Court may have closed two doors, but others have been carefully left ajar – and some wide open – leaving plenty of room for future litigation.

© Chris Greenwood and Faye Metcalfe, 4 New Square Chambers, 14th October 2025

This article is not intended as a substitute for legal advice. Advice about a given set of facts should always be taken.

[i] Munster v Lamb (1883) 11 QBD 588, 604, which the Court of Appeal cited with approval.

[ii] More particularly, the claims against them based on the disclosure of the address.  The claimant’s claim against the police contained a further strand, concerning other conduct, which was held to be arguable.

[iii] HHJ Brownhill also concluded that the claimant did not fulfil the section 7 criterion for bringing an HRA claim, however, this article will not consider this aspect of the decision nor its treatment in the subsequent appeals.