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Contact with chambers should be made through the Practice Management Team. They are happy to discuss client requirements and provide further information on such matters as the expertise and experience of individual members, fees, working practices and languages spoken. We have members able to work in French, German, Italian, Spanish, Dutch, Swedish, Greek and Chinese (Mandarin).

Outside working hours, a member of our team is always available to be contacted on matters of an urgent nature. Contact should be made using the Chambers main number or email.

For our Singapore office, for client enquiries please contact our BD Director, Asia Pacific, Lara Quie and for all other queries please contact Lynn Quek. Out of office hours calls will automatically be diverted to our clerking team in London.

London

20 Essex Street
London
WC2R 3AL

enquiries@twentyessex.com
t: +44 20 7842 1200

Singapore

28 Maxwell Road
#02-03 Maxwell Chambers Suites
Singapore 069120

singapore@twentyessex.com
t: +65 62257230

Contact

Contact with chambers should be made through the Practice Management Team. They are happy to discuss client requirements and provide further information on such matters as the expertise and experience of individual members, fees, working practices and languages spoken. We have members able to work in French, German, Italian, Spanish, Dutch, Swedish, Greek and Chinese (Mandarin).

Outside working hours, a member of our team is always available to be contacted on matters of an urgent nature. Contact should be made using the Chambers main number or email.

For our Singapore office, for client enquiries please contact our BD Director, Asia Pacific, Lara Quie and for all other queries please contact Lynn Quek. Out of office hours calls will automatically be diverted to our clerking team in London.

London

20 Essex Street
London
WC2R 3AL

enquiries@twentyessex.com
t: +44 20 7842 1200

Singapore

28 Maxwell Road
#02-03 Maxwell Chambers Suites
Singapore 069120

singapore@twentyessex.com
t: +65 62257230

Lord Verdirame KC

Lord Verdirame KC

Silk: 2019 Call: 2006

Languages: Italian (native proficiency); French and German (limited proficiency)

Lord Verdirame KC specialises in public international law, international arbitration (especially investment treaty arbitration and inter-state arbitration), human rights and constitutional law. His practice covers the full range of public international law including international dispute resolution; immunities; foreign investment protection; law of the sea; territorial and maritime boundary disputes; status of territories; human rights; use of force; law of armed conflict; international organisations; sanctions; trade.

Guglielmo is in very high demand as counsel in international arbitration, and he is particularly sought-after by investors and states for his extensive expertise and experience in investment arbitration (under BITs, ECT or investment chapters of FTAs). He has been instructed as lead counsel or counsel in many investment treaty disputes (not all in the public domain – for those that are see list below). On the investor side of his practice recent highlights include winning a  ca. US$650 million investment claim in Diag Human SE and Josef Stava v Czech Republic, PCA Case 2018-20. On the state side, they include successfully defending Ukraine from a US$6 billion Energy Charter Treaty claim, Kenya from a US$2 billion BIT claim, and the Hellenic Republic from a ca €400 million claim.

The arbitrations in which he is currently instructed range in value from hundreds of millions to several billions USD. He has worked with counsel and legal experts from dozens of different jurisdictions (both common law and civil law), and has acted in arbitral proceedings under the main institutional rules (ICSID, ICSID- Additional Facility, PCA, UNCITRAL, ICC, SCC, LCIA, Court of Arbitration for Sport).

Guglielmo regularly advise States on inter-state disputes and acts as counsel before international courts and tribunals in such disputes (including before the ICJ, ITLOS, Annex VII Tribunal under UNCLOS, the ECHR). He is counsel for Ukraine in the case brought by Ukraine against Russia in the ECHR in respect of human rights violations committed by Russia after February 2022. He was counsel for the UK in the ICJ in a dispute concerning obligations on the non-proliferation of nuclear weapons (Marshall Islands v UK), and for the Italian Republic in the Enrica Lexie Incident dispute before both the UN Tribunal for the Law of the Sea and the arbitral tribunal in the Permanent Court of Arbitration.

Guglielmo has a particularly busy advisory practice for governments, including the British Government. He is regularly instructed to advise on complex legal matters in very sensitive political, economic and diplomatic contexts (including diplomatic negotiations and political disputes). In this role, he has advised (current and former) heads of government, government ministers and senior law officers, as well as the CEOs and boards of multinational corporations.

Guglielmo is regularly instructed in cases involving international law in the English courts. He has appeared before the High Court (KBD, especially Admin Court and Commercial Court, and Family Division), Court of Appeal and the Supreme Court. He is currently counsel for the defendants in Czech Republic v Diag Human and Josef Stava (the leading challenge, involving ss. 67, 68 and 73 of the Arbitration Act 1996, to an investment treaty award in the English Courts). He is regularly instructed, including by the Foreign Commonwealth and Development Office and the UK Ministry of Defence, in cases concerning immunities, treaties, the effect of international obligations, and armed conflict. He was counsel for the government in the first Miller case on the UK’s withdrawal from the European Union, and for the UN special rapporteur on counter-terrorism and human rights in the Shamima Begum case. He was also counsel for HRH Princess Haya of Jordan in the widely reported proceedings between her and the Prime Minister of the UAE, which have led to very important judgments on the immunity of heads of government and on foreign act of State.

While he works mainly as counsel, Guglielmo has also sat as arbitrator.

Guglielmo is a Professor of International Law at King’s College London but only on a part-time basis since 2018. In the past, he was a Fellow of the Lauterpacht Centre for International Law at the University of Cambridge; a Fellow of Merton College, Oxford; and a Visiting Professorial Fellow at Harvard Law School and a Visiting Professor at Columbia Law School. He has published extensively in the field of public international law, and sits on the Advisory Board of the American Review of International Arbitration. He is working on two books: one on the relationship between international law and national law; and the other (entitled “Can Liberty Last?”) on the future of political liberty.

Lord Verdirame KC is a (non-party affiliated) member of the House of Lords, where he focuses on debates and legislation within his wider field of expertise (international law, foreign affairs and defence, arbitration, constitutional law and the protection of fundamental liberties).

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Example cases

Public international law (inter-state disputes, including disputes with/between international organisations)

Public international law & international arbitration: Investor-state arbitrations

Public international law & international arbitration: International arbitrations (other than inter-state or investor state)

International human rights law & law of armed conflict

Sanctions

Domestic proceedings (including Arbitration Act)

Publications, public engagement

Sectors and services

Professional memberships

Lectures/talks (Recent)

Education

Guglielmo is one of the leading public international lawyers in the country with vast knowledge in the field which he combines with a forensic approach to cases that is both rare and highly valuable. Hugely respected by judges – he does a first class job.

The Legal 500 UK Bar 2024

He is very calm under pressure and has a very nice manner with the tribunal. Verdirame distils things very quickly and doesn't take bum points. He makes the key points and that's where he stops.

Chambers UK Bar 2024

Guglielmo is very good at cutting to clear, crisp points.

Chambers UK Bar 2024

A stand-out silk and undoubtedly one of the very best at the Bar for investment treaty arbitration. A supremely polished and persuasive advocate. Guglielmo has excellent understanding of a client business and industry specifics, including in different regions of the world.

The Legal 500 UK Bar 2024

A very smooth and effective advocate.

Chambers UK Bar 2024

Highly knowledgeable and incredibly persuasive as an advocate.

The Legal 500 UK Bar 2023

An extremely bright barrister who is creative and prepared to give strong commercial advice.

Chambers UK Bar 2023

He explains matters so clearly, is brilliant with clients.

The Legal 500 UK Bar 2023

A master of his trade in the sphere of investor-state disputes with a fierce intellect and excellent client management skills.

Chambers UK Bar 2023

He is a persuasive advocate and just a class act.

The Legal 500 UK Bar 2023

He has very good analytical judgement and is very responsive.

Chambers UK Bar 2023

A decisive thinker who is focused in his oral contributions and effective on paper. He has a thoughtful approach that gives clients great confidence.

Chambers UK Bar 2022

Beautifully prepared, and leaves no stone unturned: novel areas and arguments don't faze him. He relishes a fight on uncertain ground and delivers brilliantly. A class act.

The Legal 500 UK Bar 2022

He's knowledgeable and thoughtful.

Chambers UK Bar 2022

Extremely erudite, very reliable and a real expert." "A very deep thinker with a deep understanding of PIL.

Chambers UK Bar 2021

Top of the list for public international law. Very strong and highly knowledgable in international issues.

The Legal 500 UK Bar 2021

A very talented international lawyer.

Chambers UK Bar 2020

Has excellent technical detailed knowledge of public international law, and is a superb advocate.

The Legal 500 UK Bar 2020

Extremely thorough, a pleasure to work with and has excellent knowledge of PIL issues.

Chambers UK Bar 2020

Particularly good in the practical application of PIL in novel commercial situations.

The Legal 500 UK Bar 2018

An excellent team player with acute insight, who has a very easy working manner.

Chambers UK Bar 2019

He has a deep intellectual knowledge, is very interested in BIT arbitration and is experienced in state-on-state matters.

Chambers UK Bar 2018

Very impressive and very highly regarded.

The Legal 500 UK Bar 2017

He's excellent and very well versed in PIL.

Chambers UK Bar 2017

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