Gary Oliver
Senior Clerk
+44 (0) 207 822 7325
Maurice has acted for numerous governments, central banks and other state-owned corporations from all continents, intergovernmental and nongovernmental organisations, multinational and national corporations, and individuals. (A partial list of clients may be provided on request, but for reasons of confidentiality it will not be complete.)
For most of his career, as well as his practice at the Bar, Maurice developed a distinguished academic reputation. As well as full-time posts at King's College London, Oxford University, and University College London, he has also held visiting professorships in the United States (twice), France (twice) and Australia, as well as giving lectures and seminars by invitation in all continents. He took early retirement from academic life in 2001, and is now Emeritus Professor of International Law at the University of London. He has also published many highly regarded courses of lectures, articles and essays. A detailed account of his academic record and full a list of his publications can be found in the "Achievements" section of his CV.
Types of work include:
Areas covered include:
Territorial sovereignty disputes; land/maritime boundary delimitation; international investment disputes and negotiation of investment protection agreements; sovereign loans; international aviation; state and diplomatic immunity and act of state; constitution and status of international organisations; international aspects of anti-trust law; international employment; compensation/damages for expropriation; state jurisdiction in territorial waters, exclusive economic zone, high seas etc; jurisdictional disputes, including extraterritorial jurisdiction; pursuit of assets of former heads of state/government; petrochemical extraction; freezing of foreign assets; state succession; international art disputes; international environment (including water resources); international protection of human rights; immigration and asylum; aspects of European Union law concerned with public international law (including legal personality, status of territory, anti-trust, anti-dumping, borrowing powers, & eligibility for membership); self-determination; state responsibility; GATT/WTO; interaction between international law and domestic law.
Maurice has also had a distinguished academic career and is Professor Emeritus of International Law in the University of London. For details, please see the achievements section at the end of his CV.
Maurice is regularly recognised as a leading silk in the latest editions of both the leading legal directories, Chambers UK and Legal 500, for his expertise in public international law and in civil liberties/human rights. Key recent quotes include:
Previous quotes include:
He is fluent in English (mother tongue) and French; competent in Spanish and Italian; and has some knowledge of German.
Maurice’s practice covers all aspects of public international law, though nowadays about two-thirds of it relates to investor protection. Other major areas include sovereignty disputes, boundary issues (land and sea), the law of the sea more generally, and the international protection of human rights. He advises and represents Governments, international organisations, corporations and (occasionally) individuals. He also sits as an arbitrator and gives expert evidence to foreign courts and international tribunals. For fuller details, please see the overview of his practice above.
As previously, Maurice is regularly ranked in the top tier of leading silks for Public International Law in the legal directories.
He has published widely on many aspects of public international law. He has also given expert testimony, by invitation, to the House of Lords Select Committee on the Arctic (July 2014), and has given written evidence to the Chilcot Inquiry into the Iraq War.
“He is extremely hard working and a genius when it comes to structuring the strategy to be adopted.”
Legal 500, 2022
“He has very strong advocacy skills, his in-depth understanding and approach to matters is commendable.”
Legal 500, 2024
“He leaves no stone unturned and is very quick to develop legal solutions to complex legal problems.”
Chambers and Partners, 2023
“As an expert, he does the job perfectly - through his thinking he sharpens the case.”
Chambers and Partners, 2023
“He's a brilliant scholar and knows how to write legal opinions in plain terms. Some experts pander to clients, but Mr Mendelson is different - he's always clear in his perspective and has outstanding integrity.”
Chambers and Partners, 2023
“He has a deep knowledge of international investment law, is a logical thinker and his advice is written in plain language, which evidences that he has a true command of very complicated and novel legal issues in international law.”
Legal 500, 2023
“A world-class legal scholar and barrister.”
Legal 500, 2023
“He's insightful, thorough and down to earth. You feel well armed and well prepared with him at your side.”
Chambers and Partners, 2022
“An absolutely excellent lawyer and pre-eminent practitioner.”
Legal 500, 2021
“One of the world’s leading public international law experts.”
Legal 500, 2018
“Has been one of the big names in the field for some time.”
Chambers and Partners, 2020
“He is uncommonly responsive and breathtakingly fast - it never fails to amaze me how quickly he puts together an opinion”
Chambers and Partners, 2017
“He is superb in the field of PIL.”
Chambers and Partners, 2018
“A first-class public international law expert.”
Legal 500, 2017
“Highly intellectual and very pragmatic – he is at the top level of leading silks for public international law”
Legal 500, 2016
Joint leading counsel for China in investment treaty arbitration (part heard).
Advised on international law aspects of major intellectual property matter involving a major biomedical process. Details confidential.
Expert opinion regarding garnishee proceedings against African judgment debtor state.
Advised a sovereign State regarding the enforcement of a multi-billion arbitral award against it.
Counsel in 3 cases in the International Court of Justice:Maritime Delimitation and Territorial Questions between Qatar and Bahrain (Qatar v. Bahrain)– for Qatar; Application for Revision of the Judgment of 11 September 1992 in the case concerning the Land, Island and Maritime Frontier Dispute(El Salvador/Honduras: Nicaragua intervening) (El Salvador v. Honduras) - for El Salvador; Land and Maritime Boundary between Cameroon and Nigeria (Cameroon v. Nigeria: Equatorial Guinea intervening)- for Cameroon
Instructed for the respondent government in a US$600m ICSID claim concerning an abortive public procurement contract.
Advising a multinational corporation on issues of state immunity et cetera in an appeal.
Advice to an Asian Government on an international investment protection dispute with a multinational corporation.
This case was concerned with whether the Republic of Serbia was bound by a contract and arbitration clause originally entered into by the State Union of Serbia and Montenegro. It raised questions concerning State identity, continuity and succession, as well as issues concerning the law of international arbitration. Maurice appeared in the International Chamber of Commerce arbitration and in the Commercial Court for the successful claimant/respondent.
This was a case concerning the civil arrest of the ARA Libertad, an Argentine warship, at the behest of NML Capital Ltd., suing to enforce a New York judgment regarding defaulted Argentine bonds. Maurice provided an expert opinion to the Ghana Supreme Court.
Sat as an arbitrator in a case under the auspices of the International Centre for the Settlement of Investment Disputes. The case was brought under the Poland-USA bilateral investment treaty, and involved the manufacture of blood plasma products.
This $40 billion international project has recently been approved by the Nicaraguan legislature. Maurice advised the Hong Kong promoter on public international law aspects of the project.
Counsel for the respondent in this case in the European Court of Human Rights.
Expert evidence in the Swiss Federal Tribunal on behalf of appellant Russian Federation against two interlocutory jurisdictional decisions of Permanent Court Arbitration investment arbitration tribunals. Judgments of 16 October 2018 (4A_396/2017, 4A_398/2017). Expert evidence also provided to various European courts (mostly appellate) in other similar cases.
Expert evidence to Eastern European court regarding human rights and criminal liability of senior politician (details confidential).
Advised various Governments on the negotiation of investment treaties and the drafting of model investment treaties (details confidential).
Advised numerous individual or corporate clients on structuring international investments or investment claims (details confidential).
Maurice Mendelson KC is a specialist in international arbitration involving States, State entities and inter-governmental organizations. His practice in this area mainly relates to international investment disputes, where he has sat as an ICSID arbitrator, appeared before and gave expert evidence to investment tribunals, participated in and advised on the negotiation and drafting of investment treaties and contracts, and advised generally. However, he has also worked in the area of commercial arbitration involving States, State entities and intergovernmental organizations, for instance in ICC arbitration and Commercial Court litigation: for example Republic of Serbia v Imagesat International NV [2009] EWHC 2853 (Comm).
International investment law and arbitration constitute around 70% of Maurice's PIL practice, for which he is praised in Legal 500 2016 as being 'highly intellectual and very pragmatic', and is ranked as a leading silk.
He has published widely in the field, and is Consultant Moderator (formerly Moderator-in-Chief) of OGEMID, the world’s leading electronic bulletin board e-forum on international investment law and arbitration.
“Great depth of expertise and arbitral experience.”
Legal 500, 2023
“His extensive experience in the relevant specialism shone through in the clear, succinct opinion provided, going straight to and focusing on the important issues.”
Legal 500, 2022
“A terrific chap to work with, commercially sound and gets the right result, clients and instructing solicitors adore him.”
Legal 500, 2019
Sat as an arbitrator in a case under the auspices of the International Centre for the Settlement of Investment Disputes. The case was brought under the Poland-USA bilateral investment treaty, and involved the manufacture of blood plasma products.
Joint leading counsel for China in investment treaty arbitration (part heard).
Instructed for the respondent government in a US$600m ICSID claim concerning an abortive public procurement contract.
Advised a sovereign State regarding the enforcement of a multi-billion arbitral award against it.
Expert evidence to Eastern European court regarding human rights and criminal liability of senior politician (details confidential).
Provided an expert opinion to this ICSID tribunal; partial award rendered 2016.
Advised various Governments on the negotiation of investment treaties and the drafting of model investment treaties (details confidential).
Giving expert evidence in a North American Free Trade Agreement arbitration, which raised questions relating to international investments. It involved issues concerning public international law and international arbitration.
Advising various third-party funders on prospects of success in various international investment cases.
Advised 2 defendants in extradition proceedings instituted in breach of an order of an international investment tribunal.
Expert evidence in the Swiss Federal Tribunal on behalf of appellant Russian Federation against two interlocutory jurisdictional decisions of Permanent Court Arbitration investment arbitration tribunals. Judgments of 16 October 2018 (4A_396/2017, 4A_398/2017). Expert evidence also provided to various European courts (mostly appellate) in other similar cases.
Advised numerous individual or corporate clients on structuring international investments or investment claims (details confidential).
This case was concerned with whether the Republic of Serbia was bound by a contract and arbitration clause originally entered into by the State Union of Serbia and Montenegro. It raised questions concerning State identity, continuity and succession, as well as issues concerning the law of international arbitration. Maurice appeared in the International Chamber of Commerce arbitration and in the Commercial Court for the successful claimant/respondent.
Maurice Mendelson KC originally practiced widely in most areas of public law and civil rights, as well as teaching it at Oxford and London Universities. However, his main speciality is public international law, and currently his involvement in civil liberties and human rights is mainly concerned with their international protection. He has, inter alia, appeared several times before the European Court of Human Rights.
“Very knowledgeable and passionate.”
Legal 500, 2018
“Very knowledgeable and passionate.”
Legal 500, 2018
“Recommended for international human rights cases”
Legal 500, 2016
“He has a wealth of expertise in international human rights law.”
Legal 500, 2015
Expert evidence to Eastern European court regarding human rights and criminal liability of senior politician (details confidential).
His most recent appearance in the European Court of Human Rights (September 2011) was in this inter-State case in which Maurice was counsel for the respondent. Expert evidence also provided to various European courts (mostly appellate) in other similar cases.
Admissibility decision: Article 1, 1st Protocol and Article 6 case concerning salvage rights etc. to a historic wreck. Maurice appeared for the unsuccessful applicants.
Advised two defendants in extradition proceedings instituted in breach of an order of an international investment tribunal.
Maurice Mendelson KC originally practiced widely in most areas of public law and civil rights, as well as teaching it at Oxford and London Universities. However, his main speciality is public international law, and currently his involvement in public law & regulatory is largely concerned with the areas where it overlaps with public international law. But it also involves such matters as assisting in the drafting of domestic constitutional provisions (abroad as well as in the UK), advising on the scope of constitutional authority; questions of self-determination; matters related to accession to the European Union; Brexit; etc.
This was a case concerning the civil arrest of the ARA Libertad, an Argentine warship, at the behest of NML Capital Ltd., suing to enforce a New York judgment regarding defaulted Argentine bonds. Maurice provided an expert opinion to the Ghana Supreme Court.
Advised on the foreshore etc. rights of a Crown dependency.
Advised the Government of India (publicly) on the right of Kashmir to self-determination.
Advised an Asian political party on the immunities of the Head of State.
Provided an opinion to the London Stock Exchange in connection with a company flotation, where he advised on aspects of the constitutional powers of the Government of South Sudan.
Advised, and gave expert evidence to the UN Security Council and General Assembly, regarding various aspects of the Cyprus situation.
Advised a fish producers organization regarding their entitlements under EU and other regulations.
Advised various corporations and individuals in relation to sanctions.
Maurice Mendelson KC has wide expertise in the areas of commercial law that involve public international law. Some of the work he has done which is listed under the “public international law” or “arbitration” sections has had commercial aspects, whether in the areas of State immunity, international arbitration, or even much of the work he has done in the area of human rights. He is a member of COMBAR, and Consultant Moderator (formerly Moderator-in-Chief) of OGEMID, the world’s leading electronic listserv on international investment law and arbitration.
Acquisition of Membership in Selected International Organizations (Oxford University, 1971).
VAT registration number: 244115592
Barristers regulated by the Bar Standards Board
Gary Oliver
Senior Clerk
+44 (0) 207 822 7325
Derek Sutton
Deputy Senior Clerk
+44 (0) 207 822 7327
Adam Sloane
Deputy Senior Clerk
+44 (0) 207 822 7326
Dean Tolman
Clerk
+44 (0) 207 822 7331
Billy Brian
Clerk
+44 (0) 207 822 7339
Marc Armstrong
Clerk
+44 (0) 207 822 7330
Adam Fuschillo
Clerk
+44 (0) 207 822 7329
Danny Compton
Clerk
+44 (0) 207 822 7338
Sophie Reeve
Clerk
+44 (0) 207 822 7324
Toby Dennison
Clerk
+44 (0) 207 822 7328
Daniel Higgins
Clerk
+44 (0) 207 822 7322
Lilly-Grace Hilliard
Clerk
+44 (0)20 7822 7234