Guy Vassall-Adams KC

Contact Guy: guyvassall-adams@matrixlaw.co.uk | +44 (0)20 7404 3447

Contact Guy's Practice Team (Team M): TeamM@matrixlaw.co.uk

Guy’s practice encompasses media and information law, public law, election law and sports law. He is recognised in the leading directories for defamation and privacy and for election law. He also acts as a mediator across the whole range of civil cases.

He is a leading specialist in media and information law, including defamation, misuse of private information, data protection and reporting restrictions, with clients ranging from individuals to media organisations, tech companies, trades unions and NGOs.

His work ranges from urgent applications through to major group litigation and from High Court trials through to appeals raising significant points of law in the Court of Appeal and Supreme Court.

Guy also regularly undertakes election law and public law cases and has appeared in a number of ground-breaking cases at the highest appellate level.

Guy is co-editor of Matrix’s book, Online Publication Claims: A Practical Guide” and the main author of the Judicial College’s Guidance, Reporting Restrictions in the Criminal Courts”.

Guy was appointed as a Deputy High Court Judge in September 2025, assigned to the King’s Bench Division. This is a part-time judicial role alongside practice at the Bar.

Media and Information Law

Guy has appeared in a number of important and high-profile cases in the fields of defamation, privacy, breach of confidence, data protection, reporting restrictions and media-related judicial reviews.

Notable cases include:

• Sinton v Maybourne Hotels [2024] EWHC 647 (KB): acting for the defendant in libel and malicious falsehood proceedings. The defendant successfully obtained summary judgment against the claims.
• R(IAB) v Home Secretary [2024] 1 WLR 1916: intervening for Justice in a judicial review successfully challenging, on the basis of the open justice principle and the duty of candour, the practice of redacting the names of civil servants.
• Global Processing Services (UK) v Yanpolsky [2023] EWHC 425 (KB): obtaining summary judgment on behalf of the claimant company in a breach of confidence case concerned with a data breach of information disclosed in criminal proceedings.
• Prighozin v Higgins: representing the defendant editor of Bellingcat in a libel claim brought by the former head of the Wagner mercenary group. The claim was highlighted as a SLAPP by the Council of Europe. It was struck out on procedural grounds.
• R(Liberal Democrats) v ITV Broadcasting Limited [2020] 4 WLR 4: representing the claimant in judicial review proceedings challenging the failure to include the party’s leader in a TV election debate.
• Lachaux v Independent Print [2020] AC 612: intervening for the Media Lawyer’s Association in the leading Supreme Court case on the serious harm test in s.1 of the Defamation Act 2013.
• MN v OP [2019] EWCA Civ 679: intervening for the media before the Court of Appeal in the test case establishing that the open justice principle applies to variation of trusts hearings.
• Rudd v Bridle [2019] EWHC 893 (QB): acting for the claimant in a data protection trial  relating to a subject access subject, where the High Court found in favour of the claimant.
• Construction Industry Vetting Information Group Litigation: acting for GMB claimants in this group litigation relating to blacklisting in the construction industry. The claims settled before trial.
• Mobile Telephone Voicemail Interception Litigation: acting for the defendant NGN in the phone hacking litigation for a 5 year period between 2011 and 2016.
• Mosley v Google Inc [2015] 2 CMLR 22: acting for the defendant in the data protection claim brought by Max Mosley relating to images made available on Google’s search engine.
• Cooper-Hohn v Hohn: [2014]: acting for the defendant in the publicity issues arising from high profile financial remedies proceedings.
• Global Torch v Apex Global Management [2013] 1 WLR 2993: acting for the media organisations in this leading open justice case before the Court of Appeal.
• Al Rawi v Security Service [2012] 1 AC 531: acting for the media intervening in this Supreme Court case on open justice, fair trials and closed material procedures.
• R(Mohamed) v Foreign Secretary [2011] QB 218: intervening for the media in the Court of Appeal and Divisional Court in a judicial review concerning open justice and redactions from a court’s judgment on grounds of national security.
• A v B (investigatory Powers Tribunal: Jurisdiction) [2010] 2 AC 1: Acting for a former intelligence officer in his Supreme Court case challenging the refusal of the Security Service to grant him permission to publish a book.
• Roberts v Gable [2008] QB 502: acting for the defendant in the Court of Appeal case about the qualified privilege/reportage defence to a libel claim.
• Jameel v Wall Street Journal Europe [2007] 1 AC 359: acting for the defendant in the House of Lords case concerning the public interest defence and the standing of companies to bring libel claims.

Guy also has a substantial advisory practice and has acted an expert on freedom of expression for the Council of Europe in Russia, Serbia, Kosovo and Armenia. Guy often gives pro bono training to campaigning organisations and non-governmental organisations on media law issues.

Group Litigation

Guy acted for News Group Newspapers for many years in the Mobile Telephone Voicemail Interception Litigation (phone hacking), the largest privacy litigation in English legal history. He also played a leading role in NGN’s own private arbitration for phone hacking cases, the Voicemail Interception Compensation Scheme, which involved a number of prominent cases.

On the claimant side, he acted for the GMB Claimants in the Construction Industry Vetting Information Group Litigation, successfully using media law torts to obtain substantial compensation for blacklisted construction workers.

Administrative and Public Law

Guy has acted in a number of high-profile judicial reviews for clients including media organisations, political parties, individuals and non-governmental organisations and also has extensive experience of intervening in judicial review proceedings.

Noteworthy cases include:

• Acting for the Migrants Rights Network (instructed by Liberty) in its successful challenge to data sharing between NHS Digital and the Home Office (MRN v NHS Digital);
• Bringing a test case on whether ITV was amenable to judicial review in relation to decisions about participants in TV election debates R(Liberal Democrats) v ITV Broadcasting Ltd [2020] 4 WLR 4.
• Acting for the claimant in the leading case challenging the current law on assisted dying: R(Nicklinson) v Ministry of Justice [2015] AC 657 (Supreme Court);
• Representing a senior former MI5 officer challenging a refusal to allow him to publish his memoirs, a case which raised jurisdictional issues about the form for challenging such decisions: (A v Security Service (Investigatory Powers Tribunal: Jurisdiction) [2010] 2 AC 1 (Supreme Court);
• Acting for the claimant in the test case on police duties towards victims of life-threatening crimes: Van Colle v Chief Constable of Hertfordshire [2009] 1 AC 225 (House of Lords).

He has intervened for the media in number of high profile judicial reviews including Binyam Mohamed v Foreign Secretary [2011] QB 218 (judgment redacted on national security grounds) (Divisional Court, Court of Appeal), M v Parole Board [213] EMLR 23 (anonymity for a prisoner seeking release) (Divisional Court), Home Secretary v Assistant Deputy Coroner for Inner West London [2011] 1 WLR 2564 (power of coroners to hold closed hearings) (Divisional Court) and R(Corner House) v Director of Serious Fraud Office [2008] CP Rep 20 (media access to JR statements of case).

His diverse cases include  intervening for a consumer rights group in a challenge to provisions of the Digital Economy Act (BT v Secretary of State for Business) and acting for a video games manufacturer in relation to a decision to ban one of its video games R(Board of Film Classification) v Video Appeals Committee [2008] 1 WLR 1658.

Election Cases

Guy has been instructed in a number of prominent election cases, most recently acting for the Prime Minister of Mauritius in Dayal v Jugnauth [2023] UKPC 37, successfully resisting a challenge to the outcome of the 2019 National Assembly election in a case concerning the correct interpretation of a bribery offence in the context of election campaigning.

He acted for the Liberal Democrats successfully resisting a claim that sought to challenge its candidate selection procedures for the European Elections on equality grounds (Dhamija v Liberal Democrats) and brought a test case on whether ITV was amenable for judicial review when choosing participants for TV general election debates (Liberal Democrats v ITV Broadcasting Ltd).  He was instructed in an appeal against fines imposed by the Electoral Commission (Electoral Commission v Leave.EU) and in cases concerning whether a significant miscount of votes voids an election (Fitch v Stephenson) and  whether a vote was void for uncertainty (Piling v Reynolds).  He is regularly asked to advise on election law issues relating to alleged violations of election law.

Sports Law

Guy has a developing practice in sports disciplinary law. He has a voluntary, part-time role as Head of Independent Judiciary at British Universities and Colleges Sport (BUCS), the national body for university sports, overseeing its sports disciplinary system. He previously represented the World Anti-Doping Association in libel proceedings brought by footballer Mamadou Sakho.

Mediation

Guy is a great believer in mediation and decided to qualify as a mediator in 2022 after participating as an advocate in a number of mediations which successfully resolved seemingly intractable disputes. Guy is a member of the Society of Mediators and is able to undertake mediations in media law, public law, human rights and commercial law.

Law Reform/Official Publications

Guy has been involved in a number of initiatives on law reform and open justice.

He is the Media Law Practitioner member of the Transparency Implementation Group, which was set up to increase the transparency of proceedings in the Family Division. He is an active member of the Media Engagement and Press Attendance and Reporting sub-groups.

Guy is a member of the Stakeholder Committee Forum of the Transparency and Open Justice Board, which is part of a wider effort to enhance open justice across the justice system.

Guy took part in the Ministry of Justice’s consultations concerning Strategic Litigation Against Public Participation (SLAPPs) which led to the anti-SLAPP law in in the Economic Crime and Corporate Transparency Act. In September 2024 Guy gave a presentation to the Department of Culture, Media and Sport on SLAPPS and other topical media law issues.

Guy is the main author of the Judicial College’s guidance, Reporting Restrictions in the Criminal Courts (2023) and the Bar Council’s guidance, Provision of documents to journalists, law reporters and other non-parties (2024).

Guy was an early supporter of the Libel Reform Campaign which culminated in the Defamation Act 2013.

Other Publications

Guy is co-editor and an author of Online Publication Claims: A Practical Guide (Matrix, 2017), a user- friendly guide to the practicalities of media law claims in relation to internet publications. Guy is also the author of online defamation training for non-governmental organisations: Online Defamation Training Course on the Defamation Act 2013

Guy is committed to protecting and respecting your privacy. In order to provide legal services to his clients, including advice and representation services, Guy needs to collect and hold personal data. This includes his client’s personal data and the personal data of others who feature in the matter upon which he is instructed. To read Guy’s privacy notice in full, please see here.

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