The Chief Constable of Sussex Police & Crown Prosecution Service v XGY [2025] EWCA Civ 1230

October 23, 2025

Court of Appeal reaffirms advocate immunity

Introduction and Case Overview

In The Chief Constable of Sussex Police & Crown Prosecution Service v XGY [2025] EWCA Civ 1230 (8 Oct 2025), the Court of Appeal reasserted the breadth of advocate and witness immunity in English law. XGY, a victim of domestic abuse, had taken pains to keep her new address confidential from her violent ex partner, DYP. During DYP’s bail hearing, a Crown Prosecutor inadvertently disclosed XGY’s confidential address in open court because the police had included it in the case file without proper warning. This breach of privacy forced XGY to relocate again and led her to sue Sussex Police and the CPS for the mishandling of her personal data, claiming psychological trauma and violations of her rights.

At first instance, the County Court struck out the claims based on the Hampshire address and entered reverse summary judgment on s.7.

XGY appealed. In a High Court appeal ruling, Ritchie J reversed the strike out, holding that the errors were administrative and not part of the core evidence, and thus potentially not covered by absolute immunity. He concluded that modern case law had shifted away from absolutism in this area towards requiring a case by case justification for immunity. However, on second appeal, the Court of Appeal, comprising Lady Carr LCJ, Sharp P and Coulson LJ, unanimously rejected that approach and reinstated the strike out. The Court of Appeal held that public policy and long established principle bar XGY from any civil remedy in these proceedings, despite the very real harm she suffered. Where an act falls within the established categories of advocate or witness immunity, it enjoys an absolute immunity from suit, even in sensitive cases like this, and even for claims under the Human Rights Act 1998 or Data Protection Act 2018.

Core Advocate Immunity and Its Extensions

Advocate’s core immunity is a longstanding common law doctrine that judges, advocates, and witnesses involved in court proceedings are immune from civil lawsuits for what is said or done in court as part of the judicial process. This absolute privilege originated to promote fearless advocacy and truthful testimony, without fear of later collateral litigation. For example, a barrister historically could not be sued for defamation over statements made in court, and a witness could not be sued for what they say on oath. Lord Hoffmann explained that, to enable those involved in the administration of justice to ‘speak freely without fear of being sued’, ‘the person in question must know at the time he speaks whether or not the immunity will attach’ Over time, the courts have extended this core immunity beyond the courtroom itself, to cover certain pre-trial or out-of-court acts that are closely connected to court proceedings. Key developments include:

Witness Statements: In Watson v M’Ewan [1905] AC 480, the House of Lords held that immunity extends to statements made by a potential witness out of court when preparing evidence for a trial. In that case, a witness’s pre trial statements to a solicitor, which later led to allegedly defamatory statements in court, were immune from a lawsuit for breach of confidence. The principle is that a person assisting in a case must be protected before they ever take the stand; otherwise, the fear of being sued over preliminary statements would chill their cooperation in the justice process. As the Court of Appeal in XGY summarised, Watson “extended immunity to statements made by witnesses outside of court where those statements were made with a view to giving evidence”.

Investigators and Case Preparation: In Taylor v Director of the Serious Fraud Office [1999] 2 AC 177, the House of Lords further extended immunity to investigators and others who are preparing the materials for a prosecution. In Taylor, a solicitor sued the SFO for defamation over a letter and a file note created by SFO officials during a fraud investigation, which suggested he was implicated in wrongdoing. Although the documents were produced before any court proceedings had commenced, and the solicitor was never actually charged or called as a witness, the Lords held the SFO was immune. Such documents were “part of the process of investigating a crime or a possible crime,” and public policy requires that investigators should be able to exchange information, theories and hypotheses without fear of being sued if such statements are disclosed in the course of proceedings. (Lord Hoffmann cautioned that this immunity for investigators would not cover matters “wholly extraneous” to the investigation, hinting that there are limits if officials stray beyond their role.)

“Wholly Extraneous” Acts: The limits of these extensions were tested in Darker v Chief Constable of West Midlands Police [2000] UKHL 44. In Darker, criminal defendants who had been wrongfully prosecuted sued police officers for allegedly fabricating evidence and perverting the course of justice. The police invoked immunity, since giving evidence is protected. The House of Lords drew a critical line: immunity does not cover acts of dishonesty or fabrication that are independent of giving evidence. Lord Hope explained that there is a distinction “between the act itself and the evidence that may be given about the act”; acts calculated to create false evidence or destroy evidence are “extraneous to the evidence that may be given” in court. In other words, an officer or witness cannot hide behind immunity if they engaged in criminal or tortious acts that go beyond their role as witnesses. Similarly, later cases have held that pressuring a witness to give false testimony, or misusing public office, falls outside immunity because the claim targets the wrongful means by which evidence was procured, not the content of any evidence given in court.

Police Sharing Information: The scenario in XGY closely parallels an earlier case, CLG v Chief Constable of Merseyside Police [2015] EWCA Civ 836. In CLG, two individuals had given witness statements about a shooting and subsequently received death threats, prompting them to relocate. When they later failed to appear in court, a police officer swore a statement to obtain arrest warrants and included their new confidential address in that statement. The statement was passed to the CPS and then, as part of the court process, disclosed to the defendants, inadvertently revealing the relocated witnesses’ whereabouts. They sued the police for negligence, breach of Articles 2 and 8 ECHR, and breach of the Data Protection Act, essentially the same menu of claims that XGY brought. The Court of Appeal in CLG dismissed the claims, holding that the police officer’s disclosure was squarely covered by immunity. Even though the address disclosure had dire consequences, it was made “for the purposes of enabling [the officer] to give evidence in court”, and to allow liability for that act “would outflank the immunity” that would protect the witness’s actual evidence in court. In other words, you cannot sue the police for the way they prepared a witness’s evidence without undermining the witness’s own immunity when testifying. The CLG court noted that the police owed no actionable duty of care to the witnesses in negligence, and it found the human rights and DPA claims likewise barred by the same immunity principle.

Together, these authorities establish a settled framework: any act that forms an integral part of the judicial process – whether it is an advocate’s statements in court, a witness’s preparation with lawyers, or a police officer’s communication of evidence to prosecutors – is protected by absolute immunity from civil suit. If the act complained of is essentially “the giving of evidence” or part of case preparation, no matter what legal label the claim bears (defamation, negligence, breach of confidence, Human Rights Act, data breach, etc.), immunity will attach. The only exceptions are where the conduct is completely outside the scope of the judicial task, for example, fabrication of evidence or other malicious acts not part of the advocate’s or witness’s function. Furthermore, while some immunities have been curtailed in recent decades – for instance, advocates can now be sued by their own clients for negligence (overruling Rondel v Worsley [1969] and Hall v Simons [2002] 1 AC 615) – those reforms did not disturb the immunity for in-court acts vis-à-vis other parties. An advocate still cannot be sued by an opponent, witness, or third party over what is said or done in the conduct of a case in court. Nor can the police or prosecutors be sued for their official actions in marshalling and presenting a case, so long as those actions are within the ambit of the judicial proceedings.

From “Justificationism” to Absolutism: High Court vs Court of Appeal

The High Court decision in XGY ([2024] EWHC 1963 (KB)) sought to recalibrate how immunity works. While the judge acknowledged that an immunity exists in law, he held that each invocation of immunity must be justified on its individual facts. He coined the term “justificationism” for this approach. Ritchie J opined that the higher courts had shown a “movement in the last 25 years… away from absolutism” in immunity doctrine, towards a “careful consideration of whether the facts of each case actually do fit within the claimed immunity by reference to whether the long-established justifications for the immunity apply.” In his view, courts should grant any extensions of immunity only “grudgingly” and, even for established categories, should examine whether in a given case the underlying policy justifications truly warrant immunity.

Ritchie J broke down the broad concept of immunity into subcategories. For example, he distinguished between acts at court, labelled “AC”, and acts before court, labelled “BC”, for both witnesses and advocates. The core immunities, he thought, covered things like testimony in court (witness AC), judges’ conduct, and an advocate’s conduct in court on matters of evidence. But other aspects, such as what Ritchie J called “Advocate’s Immunity before court (BC)” or “Legal Proceedings Immunity” for police file preparation, he viewed as extensions that might require fresh justification in each instance. He asserted that if there were factual issues suggesting the scope or necessity of an immunity was “unsettled,” the court should not strike out the case but should hear evidence and perform a balancing exercise to decide if immunity is truly necessary in the public interest on those facts. He wanted a fact-sensitive inquiry: first ask whether the conduct prima facie falls inside an immunity’s scope, and if so, then ask “does it support or undermine the justifications for that immunity?”. If the way the function was performed so undermined the justifications that the usual policy rationales (often referred to as the “swings and roundabouts” of litigation) don’t hold up, then immunity should be disallowed despite the conduct falling in the category.

Applying that framework to XGY’s case, Ritchie J found several reasons not to treat immunity as absolute. The police here, he said, were acting as “errant administrators” rather than performing a core witness or advocate function. Including the address in the file and its announcement in court were, in his analysis, “peripheral or administrative matters” not truly part of giving evidence on the live issues of the case. He noted that XGY’s address “proved nothing of the crime” and was irrelevant to the bail hearing’s substantive questions. Therefore, Ritchie J reasoned, allowing a claim in these circumstances would not actually undermine the purposes of advocate immunity: for instance, holding the CPS liable for this error would not chill an advocate’s freedom of speech in court or hinder the vigorous presentation of evidence. By contrast, he pointed out, granting immunity here might even undermine public confidence and the very rationale of witness immunity, since the very person meant to be protected – the victim herself – was harmed by the system’s lapse. In Ritchie J’s view, this scenario fell outside the heart of the immunity, or at least raised a genuine question requiring a trial. Consequently, he allowed XGY’s case to proceed on all grounds, finding that HHJ Brownhill, the trial judge, had been wrong to summarily dispose of it. Notably, he also overturned the finding that XGY lacked victim status under the HRA, suggesting that her human rights claims under Articles 2, 3, and 8 merited consideration on the evidence.

The Court of Appeal flatly rejected this reasoning and restored the orthodox approach. Lady Chief Justice Carr, delivering the judgment, held that Ritchie J had failed to apply settled law on the scope of advocate immunity. The court stressed that the immunity for words spoken by an advocate in court is an unqualified one within its established domain. It does not evaporate depending on a judge’s retrospective view of the necessity or relevance of particular words. Once the conduct in question falls within an already established immunity, no further justification is needed and no balancing test is required. The High Court’s requirement that each case be individually justified was a legal error. In the Court of Appeal’s terms, if the facts fall within an existing category of immunity, “there is no need for such individual justification.” The necessity analysis is only relevant when determining whether to create a new extension of immunity in novel circumstances (as in Taylor or earlier cases); it is “a different thing” entirely from having to justify anew an immunity that is already settled law.

The Court of Appeal dismantled Ritchie J’s reinterpretation of the authorities. For example, he had read Taylor and Darker as implying that immunity must be shown to be necessary in each instance, or that “extraneous” information might fall outside immunity. The Court of Appeal corrected this: Taylor’s discussion of necessity was about whether to extend immunity to investigators in the first place, not about applying an extension that plainly covered the facts. And Darker, rather than “modifying” Taylor, expressly approved it. Lord Hope’s point in Darker was simply that outright fabrication of evidence is not protected – a scenario far removed from XGY’s case. XGY’s address disclosure may have been ill-advised, but it was not an independently tortious act like evidence tampering; it occurred in the course of legitimate case preparation and court argument. Thus, Ritchie J’s reliance on Darker was misplaced. Similarly, he attempted to distinguish the 2015 CLG precedent by arguing that in CLG the address was “crucial evidence” for an arrest warrant whereas XGY’s address was “confidential and not to be used in evidence” at trial. The Court of Appeal found this difference immaterial. The CLG situation and XGY’s were, in substance, no different – both involved police handling a victim’s address as part of the case file and a prosecutor unwittingly revealing it in court. In both cases, the disclosure was intimately connected to the judicial process (a warrant application in CLG, a bail hearing in XGY). Therefore, the same result had to follow. To hold otherwise would outflank the core immunity of the advocate: if the police could be sued for passing along the information, or the CPS sued for the advocate’s statement, it would undermine the immunity that the advocate and witness enjoy for the proceedings themselves.

The Court of Appeal was also troubled by the practical implications of Ritchie J’s approach. If every instance of an advocate’s speech had to be litigated for justification, the certainty of immunity would be lost and advocates would operate under fear of personal liability for any misstep. The CPS appellants argued that immunity would become unworkable if the application of the immunity in any given case could only be determined after the event. The court agreed: such a regime defeats the very purpose of immunity, which is to allow participants to focus on their duties without constantly looking over their shoulder for potential lawsuits. Moreover, carving a dubious distinction between evidential matters and administrative matters, as Ritchie J attempted, is unrealistic in practice. The Bar Council, intervening in the appeal, pointed out that especially in criminal, family, and other sensitive cases, advocates routinely handle information that might be considered administrative or private, such as addresses and health information, intertwined with the evidence. It would be confusing and onerous to ask courts and lawyers to parse which parts of their case preparation are immune and which are not. The Court of Appeal disagreed with Ritchie J’s central conclusion that the core immunity was somehow inapplicable here. The appellate judges found his interpretation based on an incorrect reading of the authorities, and a departure from centuries of precedent. They restored the orthodox absolute approach: the CPS advocate’s announcement of the address in court was an instance of something said in judicial proceedings, and the police officer’s inclusion of the address in the case file was part and parcel of preparing evidence for those proceedings. Both acts fell within established immunity, so no further inquiry was necessary or permissible.

In the result, the Court of Appeal set aside Ritchie J’s order and reinstated the strike out of all XGY’s claims. XGY’s lawsuit against the police and CPS was dismissed in its entirety on the principal ground of immunity: the prosecutor’s courtroom disclosure was protected by core advocate immunity, and the police’s handling of the address was protected by the well established extension of that immunity to those assisting in the preparation of a case. The court also noted that, in any event, XGY was unlikely to meet the threshold for a Human Rights Act claim on these facts. HHJ Brownhill’s conclusion that she lacked the necessary standing as a victim under the HRA, section 7(7), was upheld. And, critically, the judges underlined that neither the HRA nor the Data Protection Act can be used as a means to circumvent immunity. There was no indication in either statute that Parliament intended to cut across or abolish these common law immunities. Absent express words or necessary implication in the legislation, the longstanding immunities continue to bar even statutory or Convention claims based on the same impugned act.

The Court cited Crawford as confirming that a claim for breach of a statutory duty is subject to the same immunity defences as any common law claim. In short, repackaging the grievance as a data breach or privacy violation does not allow a claimant like XGY to escape the immunity hurdle.

The Court of Appeal expressed sympathy for XGY. Lady Carr noted that “nothing that we have said is intended to detract from the consequences for XGY of the disclosure of her address… We would wish to express our sympathy for her and the situation in which she was placed.” Yet, the court concluded, “public policy and long-established principle mean that she does not have a legal remedy in these proceedings for what happened.” In other words, the injustice she suffered is one the law must tolerate in order to uphold a greater systemic principle.

Implications for Practitioners, Victims, and Advocates

The ruling confirms that police, prosecutors, and investigators are broadly protected from civil liability for actions taken during crime investigation and prosecution, even for statutory claims like data breaches, provided these arise from core trial processes. However, this immunity does not excuse mishandling of sensitive information; such errors can still cause harm, trigger disciplinary action, and damage public trust. Practitioners must therefore strictly adhere to protocols for handling victim data, remembering that immunity safeguards honest work, not negligence.

Victims must turn to mechanisms like police complaints procedures, Victims’ Commissioners, or Ombudsmen to address grievances, as civil lawsuits are barred. In serious instances, judicial review or protective injunctions (such as confidentiality orders) may be available, but damages are not. The Court of Appeal did not rule out human rights arguments entirely, yet made clear the threshold is high. This situation may drive calls for improved statutory remedies or stricter data protection enforcement in the justice system.the Court held that claims under the HRA or DPA cannot evade the common-law immunity: absent express statutory words, the longstanding advocatewitness immunity bars even Convention or statutory claims based on the same act

For advocates, barristers, solicitor advocates, and legal professionals the decision provides welcome reassurance, reaffirming absolute courtroom immunity and shielding them from retrospective litigation over their conduct in proceedings. If Ritchie J’s approach had been upheld, advocates might have faced lawsuits for any questionable disclosure, undermining their ability to act robustly in court. The Court of Appeal’s clear rule ensures that, provided advocates act in good faith within their remit, they are protected from personal liability. This supports candid advocacy and fearless witness examination, essential for justice. Nonetheless, immunity does not cover misconduct such as fabricating evidence or suborning perjury, which remain subject to legal and professional sanctions. Lawyers must also maintain high ethical standards and take care to protect confidential information, particularly in sensitive cases. The Bar Council’s involvement in XGY underlined the importance of clear guidelines for managing sensitive data to prevent such errors.

Conclusion

The XGY decision reaffirms advocate and witness immunity, rejecting attempts to erode these protections through case by case analysis. For legal professionals, it provides reassurance that civil liability remains limited when acting within their official duties, but also highlights that individuals like XGY may suffer harm without legal remedy. The case will stand as the Court of Appeal’s authoritative statement that absolute advocate immunity persists, safeguarding the integrity of judicial proceedings even in difficult circumstances.

Further Reading

• What is Absolute Privilege?
• Professional Negligence Claims
• Solicitor Negligence 
• Misuse of Private Information 
• Defamation