Mark Henderson

Practice Areas

Media, Defamation and Freedom of Expression

Data Protection and Information Law

Administrative & Public Law

Immigration

Inquests and Public Inquiries

Actions Against the Police and Public Authorities

Immigration Detention Group

Career

Mark specialises in media, public and human rights law.

He has acted in numerous leading media, human rights, and public law cases over the last 25 years. Clients have ranged from the Leader of the Opposition to survivors and bereaved in the Grenfell Tower Inquiry. He has developed and acted in strategic litigation in the UK (e.g. winning the right to settle in the UK for thousands of Gurkha veterans) and in Europe (e.g. securing human rights protection for thousands of asylum seekers subject to inter-state transfers under the Dublin regime). He is accustomed to working on test cases in tandem with public campaigns (such as the award winning Gurkha Justice Campaign). He has acted for national and international NGOs in public interest interventions at the highest level, in addition to handling interventions in his own cases (such as Amnesty International, the Equality and Human Rights Commission, UNHCR and numerous EU member states). He was appointed Standing Counsel to the Labour Party in 2019.

He is instructed as lead counsel against silks in both domestic and international courts. International cases include the landmark European Court of Justice case of McCarthy, in which he defeated the UK’s claim to a unilateral right to suspend free movement rights.

He developed the seminal case of NS as the first challenge to the UK’s claimed opt out from the Charter of Fundamental Rights and the lead case across the EU on member states’ human rights duties when making interstate transfers of asylum seekers under the Dublin system. He acted as lead counsel in the High Court against a silk led team, and appeared as lead advocate in the Court of Justice Grand Chamber.

Domestically, he was lead counsel for the Labour Party in one of the most politically important and sensitive cases ever heard by UK courts, in which he led its successful defence of the National Executive Committee’s ruling on members’ entitlement to vote for the incumbent Leader of the Party in a leadership election.

He has acted in some of the most high profile defamation litigation in recent years, such as a 2021 Court of Appeal judgment in which he defended the former Leader of the Opposition for answers given on BBC One’s Andrew Marr Show when interviewed as Leader, and in defence of the free speech of a major trade union in a case identified in commentary as one of the top 10 cases of 2019 across common law jurisdictions. He acted as sole counsel for the Labour Party in the most high profile defamation case it has ever faced.

He has won extremely large damages in recent years against the BBC and almost all national newspapers in libel, privacy, harassment by publication, and data protection claims. His clients have included politicians, journalists, activists, NGOs, a TV station, and a former Guantanamo detainee.

He also acts extensively for defendants including non-traditional newspapers, online news and bloggers, trade unions, politicians, activists, political parties, and others who face defamation claims for what they have said, often concerning issues of public importance, on mainstream media, on blogs/social media, and in print. His work as Standing Counsel to the Labour Party has involved advising on defamation, privacy and data protection issues, often fast moving and of national and political importance. He acts for trade unions in industrial disputes in defamation and harassment actions brought in defence of their members, and has acted in defence of their free speech against libel action by corporations with whom they are in industrial dispute.

The application of human rights to media and communications cases is one of his specialities. His public law and standards work includes leading free speech/Art 10 and privacy/Art 8 judicial reviews and appeals (below). He also acted in one of the leading Strasbourg authorities defining the scope of private life in Art 8 and in an Art 10 case on the regulation of offensive speech on broadcast media.

He acted for 66 bereaved and survivors in Phase 1 of the Grenfell Tower Inquiry which resulted in detailed findings on the events on the night of the fire, and conclusions that the Tower did not comply with building regulations designed to prevent the spread of fire and that inadequacies in the emergency services’ planning and response on the night contributed to the loss of life. It made numerous recommendations aimed at improving planning for high rise fires and the emergency response to them, and on warning and evacuation measures.

He has appeared in numerous leading asylum and immigration cases, including a series of test cases which protected all Zimbabweans from expulsion to that country for a number of years because of risk of ill-treatment by the Mugabe regime, culminating in a landmark ‘country guidance’ ruling that a large proportion of Zimbabwean claimants were entitled to refugee status. He has also acted in several leading judicial reviews and civil claims for unlawful detention against the Home Office, winning judgments that include a ruling that the Home Secretary’s practice of using administrative detention powers to detain Foreign National Offenders pending criminal prosecution was unlawful.

In the British Army Gurkha judicial review, he acted from the outset in the test case which overturned the UK Government’s decades-old refusal to allow Gurkha veterans to settle in the UK. Combined with a public campaign, this led to the Government’s defeat in the House of Commons and to a right to settle for thousands of veterans. He was a member of the delegation that collected the Human Rights Award from Justice and Liberty on behalf of the Gurkha Justice Campaign for their victories in the High Court and in Parliament.

Many of his human rights and public law cases have tested and expanded the boundaries of disclosure and candour duties owed by ministers and public authorities. Leading judgments on the duty of candour in judicial review include a ruling giving emphatic guidance to ministers and the Government Legal Department on their duty of candour, which followed a long disclosure battle in the Administrative Court to obtain internal Home Office documents about detention and removals.

Leading freedom of expression/ Art 10 challenges for journalists and elected representatives include case of S which expanded privacy rights in public law. He won the first ruling that the Home Secretary’s No Recourse to Public Funds (NRPF) policy was unlawful by reason of breach of the Public Sector Equality Duty (PSED) to disabled people. Other Equality Act cases have challenged policies and decisions of public authorities on grounds of disability, race, sex and age, including ground-breaking challenges testing ministers’ duties under the PSED when critical public services are contracted out.

His landmark human rights work as lead advocate in the Court of Justice is mentioned above. In the European Court of Human Rights, as well as the Art 8/private life and Art 10/free speech cases noted above, other leading authorities include the first ever successful Strasbourg challenge to confiscation under the Proceeds of Crime Act 2002, in which the ECtHR held that confiscation violated the right to peaceful enjoyment of property under A1, P1.

Public interest interventions at the highest domestic level have included acting for 14 organisations, including Amnesty International, Human Rights Watch, and the Law Society, in the internationally acclaimed case which established that no circumstances could permit the admission of evidence obtained through torture, and for Liberty in an intervention arguing that the Special Advocate regime in terrorism cases was incompatible with common law constitutional rights and the ECHR.

Governance, standards and regulation: contractual rules and governance of unincorporated associations, including political parties; public standards codes for elected representatives; statutory and contract based regulation, especially media related; election law and regulation of campaigning, including electronic communications.

He has acted in some of the leading freedom of expression authorities on media regulation and on public standards codes governing elected representatives. He was lead counsel against a silk led team for the Public Services Ombudsman in the leading High Court appeal on the application of Art 10 to public standards codes (which quashed the sanction for the way in which a councillor had criticised officers as being a disproportionate interference with the councillor’s freedom of speech).

He acted in the leading case on the application of Art 10 to broadcasting regulation, which established the domestic law right of individual journalists, broadcasters and presenters to challenge Ofcom rulings in which their speech is held to have contravened the Broadcasting Code.

He has advised the Labour Party and the Leader of the Opposition’s Office for several years on national constitutional and legal issues, and party compliance, disciplinary, equality, and governance issues (including, from 2019, as Standing Counsel to the Party).

Professional Memberships

Bar Council Disability Panel (Chair)

Administrative Law Bar Association

Bar European Group

Immigration Law Practitioners Association

Liberty

Spinal Injuries Association (Board Trustee and former Vice Chair)

ParaPride (Ambassador)

Education