Philippa’s practice covers all aspects of public international law. She acts for states and private entities in domestic and international courts on a wide range of issues. These include state and diplomatic immunities, territorial and maritime boundaries, treaty obligations, law of the sea, state responsibility, human rights, humanitarian law, law of international organisations and international criminal law.
She has been described as “the foremost expert on state immunity” and is counsel in ground-breaking cases in international and English courts. Philippa advises on all aspects of immunity, including immunity from enforcement, diplomatic status, and related concepts such as act of state. She is appointed to the Attorney General’s Public International Law B Panel of Counsel.
Philippa is a specialist in relation to the International Court of Justice (ICJ). She served as the Legal Officer and Special Assistant to Judge Rosalyn Higgins GBE KC during her presidency and in this capacity was involved in 15 inter-state cases. Philippa has since appeared as counsel and advocate in 7 ICJ cases. Philippa has also worked as a legal adviser at the ICC.
She is Professor of Public International Law at King’s College London and Director of the Centre for International Governance and Dispute Resolution. She has held visiting positions at the University of Oxford, the Graduate Institute in Geneva, the University of Notre Dame and Université Paris Nanterre. She is on the Committee of Legal Experts for the Commission of Small Island States on Climate Change and International Law.
From September 2024, Philippa will be Professor of Public International Law at the University of Oxford and the Blavatnik School of Government.
Philippa was shortlisted for 2022 “Barrister of the Year” by The Lawyer. She has been ranked as a top junior in Public International Law, a ‘Future Leader’ in arbitration and a ‘UK Bar: Rising Star’.
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Example cases
- International Court of Justice: Guatemala’s Territorial, Insular and Maritime Claim (Guatemala/Belize): counsel to Belize in the dispute concerning Guatemala’s claims to territory and maritime areas.
- UK Supreme Court: Wong v Basfar, [2022] UKSC 20: counsel to the claimant in the first case in the world in which a leading court has concluded that the alleged exploitation of a domestic worker in circumstances of modern slavery falls within the “commercial activity” exception to diplomatic immunity in Article 31(1)(c) of the Vienna Convention on Diplomatic Relations 1961 (led by Tim Otty QC).
- English High Court: Al Masarir v Kingdom of Saudi Arabia [2022] EWHC 2199: counsel to the claimant in a case ruling that Saudi Arabia is not immune under the UK State Immunity Act for alleged use of spyware to infiltrate the iPhones of a prominent human rights activist. The first case to find an exception to sovereign immunity for allegations related to spyware (led by Richard Hermer QC).
- International Court of Justice: Application of the Convention on the Prevention and Punishment of the Crime of Genocide (The Gambia v. Myanmar): counsel to The Maldives as an intervenor in the case in support of The Gambia.
- International Court of Justice: Allegations of Genocide under the Convention on the Prevention and Punishment of the Crime of Genocide (Ukraine v. Russian Federation): counsel to a state intervening in support of Ukraine.
- European Court of Human Rights: Ukraine v. Russia (X), counsel to Ukraine in a case against the Russian Federation arising from the invasion of Ukraine in February 2022.
- International Court of Justice: Legal consequences of the separation of the Chagos Archipelago from Mauritius in 1965 (Request for Advisory Opinion): counsel to the UK in advisory proceedings before the ICJ raising issues of decolonisation, self-determination and judicial discretion.
- International Court of Justice: Maritime Delimitation in the Indian Ocean (Somalia v Kenya): counsel to the Republic of Kenya in a dispute over the maritime boundary between the two States pending before the ICJ. This is the first time that either State has come before the ICJ.
- Inter-State Arbitration: The Enrica Lexie Incident (Italy v India): counsel to the Italian Republic in a case before the Permanent Court of Arbitration concerning an incident approximately 20.5 nautical miles off the coast of India involving the “Enrica Lexie”, an oil tanker flying the Italian flag, and India’s subsequent exercise of criminal jurisdiction over the vessel and two Italian marines from the Italian Navy (led by Daniel Bethlehem QC).
- UK Supreme Court: Reyes v Al-Malki [2017] UKSC 61: counsel to the intervenor (Kalayaan) in a case on diplomatic immunity. The appeal was unanimously allowed, with the court holding that the former diplomat did not enjoy immunity for the employment and alleged mistreatment of his domestic servant (led by Richard Hermer QC).
- Privy Council: Botas Petroleum Pipeline Corporation v Tepe Insaat Sanayii AS [2018] UKPC 31: counsel for the respondents in an appeal to the Privy Council in a case on the meaning of “property of a state” in an enforcement context. It held that state immunity does not extend to the property of state-owned entities. Such property is not to be considered “property of a state” that is immune from enforcement (led by Stuart Catchpole QC).
- The Freedom And Justice Party and others, R (On the Application Of) v The Secretary of State for Foreign and Commonwealth Affairs and another (Rev 2) [2018] EWCA Civ 1719: counsel for the appellants in a case concerning special missions immunity and allegations of torture (led by Sudhanshu Swaroop QC).
- PAO Tatneft v Ukraine[2018] EWHC 1797 (Comm): counsel to Ukraine in a case concerning an effort to enforce a US$112 million investment BIT award in favour of Russian oil producer Tatneft against Ukraine, raising issues of state immunity (led by Philip Edey QC).
Public international law
Philippa advises clients from all over the world on a wide range of international law issues. She has acted as counsel in cases before the ICJ, PCA, ECtHR and ITLOS. During her time at the ICJ, she worked on 15 cases involving the law of the sea, territorial sovereignty, immunities, genocide, the use of force, human rights, diplomatic protection, and environmental matters.
Her expertise is recognized by her appointment to the International Advisory Panel for the American Law Institute’s project Restatement Fourth, Foreign Relations Law of the United States. She is also appointed to the Attorney General’s Public International Law B Panel of Counsel.
Philippa was elected to the Board of the European Society of International Law (2016-2020). She is a member of Public International Law Advisory Panel, British Institute for International and Comparative Law, a Board Member of the Young Public International Law Group, and a member of the Committee of Legal Experts for the Commission of Small Island States on Climate Change and International Law. She is also appointed to the Legal Task Force for Accountability for Crimes Committed in Ukraine.
She is Professor of Public International Law at King’s College London and has published 5 books and more than 50 articles and chapters on international law.
Her lecture for the United Nations Audiovisual Library of International Law is available here.
- International Court of Justice: Guatemala’s Territorial, Insular and Maritime Claim (Guatemala/Belize), pending
- International Court of Justice: Application of the Convention on the Prevention and Punishment of the Crime of Genocide (The Gambia v. Myanmar), counsel for The Maldives as intervenor, pending
- International Court of Justice: Allegations of Genocide under the Convention on the Prevention and Punishment of the Crime of Genocide (Ukraine v. Russian Federation), counsel to a state intervening in support of Ukraine, pending
- European Court of Human Rights: Ukraine v. Russia (X), counsel to Ukraine, pending
- International Court of Justice: Legal consequences of the separation of the Chagos Archipelago from Mauritius in 1965, Advisory Opinion 2019
- International Court of Justice: Maritime Delimitation in the Indian Ocean (Somalia v Kenya)
- ITLOS Case No. 24 The “Enrica Lexie” Incident (Italy v India) – Counsel to the Italian Republic.
- PCA Case No. 2015-28: The “Enrica Lexie” Incident (Italy v India) – Counsel to the Italian Republic.
- Botas Petroleum Pipeline Corporation v Tepe Insaat Sanayii AS [2018] UKPC 31
- Advising the FCDO on international law matters (confidential)
- Advising an international organization on its immunities in relation to locally engaged persons.
- Advising a state on human rights issues arising in a bilateral relationship with another state.
- Advising a company on foreign act of state and sovereign immunity issues in the context of arbitration and related proceedings in the English court.
- Advising a former head of state on immunity issues in proceedings in the English court.
Human rights
Philippa acts and advises in relation to a wide range of human rights issues before domestic and international courts and bodies. She is the co-author of The Right to a Fair Trial in International Law (OUP 2021, with Amal Clooney), which has been described as ‘a tour de force’ (Karim Khan QC, International Criminal Court Prosecutor-elect), ‘a must-read book for everyone in the field: judges, scholars, students, civil servants, NGOs and all over the world’ (Judge Tulkens, former VicePresident of the ECtHR), ‘the definitive work now on fair trial rights’ (Professor van Schaack, Stanford University), ‘An outstanding book … It creates the basis by which a vigilance can be exercised’ (Zeid Ra’ad Zeid Al Hussein, former UN High Commissioner for Human Rights), and ‘essential for judges at all stages of proceedings and academics and students’ (Judge Sir Howard Morrison KCMG CBE QC, British Judge at the International Criminal Court. She has conducted training on human rights for government officials in the UK and overseas. She is Board Member and Secretary of the Clooney Foundation for Justice and on the Bar Panel of Human Dignity Trust. She is ranked in directories for international human rights law.
Her recent experience includes:
- English High Court: Al Masarir v Kingdom of Saudi Arabia [2022] EWHC 2199: counsel to the claimant in a case ruling that Saudi Arabia is not immune under the UK State Immunity Act for alleged use of spyware to infiltrate the iPhones of a prominent human rights activist. The first case to find an exception to sovereign immunity for allegations related to spyware.
- Counsel to a state intervening in a case before the International Court of Justice concerning allegations of genocide.
- Counsel to a claimant before the United Nations Human Rights Committee.
- Counsel in a case before the European Court of Human Rights brought by an entity against Turkey for violations of the European Convention on Human Rights, including the right to property and freedom of thought, conscience and religion
- Counsel in leading cases on diplomatic immunity and allegations of modern slavery:
- UK Supreme Court: Wong v Basfar, [2022] UKSC 20: counsel to the claimant in the first case in the world in which a leading court has concluded that the alleged exploitation of a domestic worker in circumstances of modern slavery falls within the “commercial activity” exception to diplomatic immunity in Article 31(1)(c) of the Vienna Convention on Diplomatic Relations 1961 (led by Tim Otty QC).
- Reyes v Al-Malki[2017] UKSC 61 – Counsel to the intervenor, Kalayaan. The appeal was unanimously allowed, with the Court holding that the former diplomat did not enjoy immunity for the employment and alleged mistreatment of his domestic servant.
- Ms C Reyes and Ms T Suryadi -v- Mr J Al-Malki and Mrs Al-Malki and Others[2015] EWCA Civ 32 – advised the intervenor, Kalayaan, in this case on the interaction between diplomatic immunity, the State Immunity Act 1978 and European law.
- The Freedom and Justice Party and others, R (On the Application Of) v Secretary of State for Foreign and Commonwealth
- Affairs & Anor [2018] EWCA Civ 1719 and The Freedom and Justice Party and others, R (On the Application Of) v Secretary of State for Foreign and Commonwealth Affairs & Anor[2016] EWHC 2010 (Admin)The case concerned allegations of torture and the customary international law on special missions immunity.
- Advised Amnesty International (with Sudhanshu Swaroop QC) on an Amicus Intervention before the Constitutional Court of South Africa in a case concerning the immunity of President al-Bashir of the Sudan.
- Bobby James Moore v Texas, Docket Number 15-797 United States Supreme Court – Death penalty case. I was Amicus on the Brief of International Law and Human Rights Institutes, Societies, Practitioners and Scholars as Amici Curiae in Support of Petitioner’s Application for Certiorari, 2016.
- Legal advisor to the UN Special Rapporteur on Counter-Terrorism and Human Rights regarding the inquiry into the legality of drones (2013).
- Legal advisor to a State regarding the International Criminal Court, including forming part of the official delegation to the Kampala Review Conference (2010).
- Legal advisor to a State regarding its treaty obligations (including reporting to treaty bodies) under the Convention against Torture and the International Covenant on Civil and Political Rights (2010-2015).
Arbitration
Philippa is ranked as a ‘Future Leader’ by Who’s Who Legal.
She has experience with inter-state litigation and is in gaining experience in investment treaty and commercial arbitrations, under the ICSID and UNCITRAL Rules, including in the related proceedings before English courts involving resistance to or enforcement of awards. She was invited to speak on immunity and act of state issues in arbitration on the occasion of the 125th Anniversary of the Commercial Court in 2020.
Counsel to a company in an arbitration and in related enforcement proceedings in the Commercial Court concerning a state’s cancellation of a lucrative mining licence. The state eventually settled on terms very favourable to the company.
- Privy Council: Botas Petroleum Pipeline Corporation v Tepe Insaat Sanayii AS [2018] UKPC 31: counsel for the respondents in an appeal to the Privy Council in a case on the meaning of “property of a state” in an enforcement context. It held that state immunity does not extend to the property of state-owned entities. Such property is not to be considered “property of a state” that is immune from enforcement (led by Stuart Catchpole QC).
- Counsel to Ukraine in a dispute before the Commercial Court relating to the enforcement of a foreign arbitral award.
PCA Case No. 2015-28: The “Enrica Lexie” Incident (Italy v India) – Counsel to the Italian Republic in a case concerning a dispute involving human rights, immunities and the law of the sea. The Award was issued in 2020.
