Call: 1989

Jill was called to the Bar in 1989 and is a member of Gray’s Inn.

Jill Barrett is Visiting Reader in the School of Law at Queen Mary University of London, where she teaches public international law to postgraduate students. She also works as an independent consultant in public international law. She is currently Research Consultant to the Centre for International Law, Singapore, engaged on a project to deliver training in treaty law and procedures to government and international organisation officials in the Southeast Asian region and publish a handbook on this subject. Jill also advises on questions of treaty law and practice in relation to international investment treaty disputes and provides expert evidence in treaty arbitrations.

Until recently, Jill was the Arthur Watts Senior Research Fellow in Public International Law at BIICL, where she designed and led the Watts programme of international law research and events. She specialises in the law and practice of treaties, the polar regions, international environmental law and law of the sea. Her recent publications include Barrett and Barnes (eds), Law of the Sea: UNCLOS as a Living Treaty, (BIICL 2016); ‘Securing the Polar Regions through international law’ in Footer et al (eds) Security and International Law (Hart 2016); and Barrett et al, Report on the Obligations of States under Articles 74(3) and 83(3) of UNCLOS in respect of Undelimited Maritime Areas, BIICL 2016. She was Visiting Professor in International Law at Kobe University, Japan, in 2013.

Jill was previously Legal Counsellor at the Foreign & Commonwealth Office. During her 20-year FCO career she advised on legal aspects of UK foreign policy, and represented the UK at the United Nations and a variety of international conferences including Antarctic Treaty Consultative Meetings, CCAMLR, London Convention, International Whaling Commission, and the UN Commission on Environment and Development. She was Deputy Agent for the UK in the Mox Plant cases brought by Ireland under UNCLOS and the OSPAR Convention. Before joining the FCO, she was Lecturer in Law at SOAS, London University, specialising in the People’s Republic of China, and Lecturer in Law at Durham University.



LLM from Cambridge University (First Class)
BA Hons in Law from Durham University (First Class).

Latest news

1st February 2024

Jill Barrett’s witness evidence cited in ‘Parliamentary Scrutiny of International Agreements in the 21st century’

Parliament’s report on 'Parliamentary Scrutiny of International Agreements in the 21st century’, published 29th January, cites Jill Barrett’s witness evidence. On 29 January 2024...

9th February 2022

Jill Barrett gives evidence to parliamentary inquiry on international treaty scrutiny

Jill Barrett gives evidence to the parliamentary inquiry on 'The Scrutiny of International Treaties and other international agreements in the 21st century’.

9th July 2021

Parliament, Trade and Treaties

Jill Barrett will be one of a panel of expert speakers on ‘Parliament, Trade and Treaties’ at a live online event hosted by the Institute for Government on 13 July.

9th November 2020

International arbitration awards: challenges and enforcement

Six Pump Court Chambers are delighted to host a series of webinars on international arbitration.

13th July 2020

Jill Barrett advises new International Agreements Committee of the House of Lords 

In April this year Parliament set up its first ever treaty committee, to improve scrutiny of the UK’s increased treaty-making since leaving the EU.

8th April 2020

Handbook on Good Treaty Practice

We're pleased to announce publication of the 'Handbook on Good Treaty Practice’ by Jill Barrett and Robert Beckman.

24th March 2020

Parliament and Brexit – a new Report

A report on "Parliament and Brexit’ was published today by UK in a Changing Europe. It explores the role Parliament has played to date on Brexit, as well as the challenges and opportunities .

29th November 2019

Jill Barrett speaks at Polar Law Symposium in Australia

Jill Barrett will be attending the 12th Polar Law Symposium in Australia, an annual gathering of the world’s leading specialists in the law of Antarctica and the Arctic.

9th October 2019

Jill Barrett gives evidence on treaty scrutiny to parliamentary committee

Jill Barrett has submitted written evidence to the House of Commons Public Administration and Constitutional Affairs Committee’s Inquiry on Parliamentary Scrutiny of Treaties.

7th May 2019

Jill Barrett consulted by Parliamentary Committees on Treaty Scrutiny

Jill Barrett has submitted written evidence to the House of Lords Select Committee on the Constitution's Inquiry on Parliamentary Scrutiny of Treaties, at the request of the Committee.

18th March 2019

International Court of Justice’s Advisory Opinion on the Chagos Islands: Seminar

Jill Barrett will chair a rapid response seminar today to discuss the International Court of Justice’s Advisory Opinion on the Chagos Islands.

17th December 2018

International law and governance of the Polar Regions

Jill Barrett is in Japan participating in an international symposium on International Law for Sustainability in Arctic Resource Development: Integrating Economic, Social, Environmental and Scientific Dimensions.

17th May 2018

Jill Barrett speaks at the 2018 Global Ocean Regime Conference

Jill Barrett is in South Korea participating as an invited speaker in the 2018 Global Ocean Regime Conference.

3rd May 2018

Jill Barrett gives evidence to House of Commons Committee on Exiting the EU

Jill Barrett gave oral evidence on 2 May 2018 to the House of Commons Committee on Exiting the European Union, as part of its inquiry on the progress of the UK’s negotiations on EU withdrawal.

22nd March 2018

Treaties, Brexit and the Constitution

Jill Barrett will speak on "Parliament’s role in negotiating, concluding and implementing treaty obligations and the Constitutional Reform and Governance Act 2010".

14th November 2017

Legal consequences of the separation of the Chagos Archipelago from Mauritius (ICJ Advisory Opinion)

Jill Barrett has been invited to chair a BIICL seminar on 11 December 2017.

1st November 2017

The marine environment after Brexit – the UK’s international law obligations

Jill Barrett spoke at a conference hosted by the British Ecological Society and the Marine Biological Association.

24th July 2017

Maritime Delimitations and Hydrocarbon Resources in Central America and the Caribbean

Jill Barrett spoke at a conference on Maritime Delimitations and Hydrocarbon Resources in Central America and the Caribbean.

4th November 2016

Jill Barrett joins Six Pump Court as an Associate Member

Six Pump Court is pleased to welcome Jill Barrett, a distinguished academic and former FCO lawyer in the field of public international law as...