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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 Head of Business Development for Asia Pacific, Katie-Beth Jones, and for all other queries please contact Lynn Quek. Out of office hours calls will automatically be diverted to our practice management 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 Head of Business Development for Asia Pacific, Katie-Beth Jones, and for all other queries please contact Lynn Quek. Out of office hours calls will automatically be diverted to our practice management 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

Jonathan Ketcheson

Jonathan Ketcheson

Call: 2016 (England and Wales); 2022 (British Virgin Islands)

Jonathan practises across all Chambers’ areas of expertise, with a particular focus on international arbitration and investment treaty arbitration. He has acted for states and investors in investment treaty arbitrations, under both the ICSID Convention and the UNCITRAL rules. Jonathan has also acted for companies in international commercial arbitrations under the ICC, LCIA and LMAA rules. He is also appointed to the Attorney General’s Public International Law C Panel of Counsel.

He initially qualified as a solicitor in Australia, practising in commercial litigation, before working as an associate to Justice Crennan of the High Court of Australia. Jonathan was also a senior associate at Hogan Lovells in London, specialising in investment treaty arbitration, public international law and international arbitration.

Prior to joining the bar, Jonathan was a research assistant to Professor James Crawford (later Judge Crawford of the International Court of Justice) and completed a doctorate on international dispute settlement at the University of Cambridge under the supervision of Professor Crawford and Professor Zac Douglas. Jonathan was also an assistant to the Bahrain Independent Commission of Inquiry.

He was admitted to the Bar of the East Caribbean Supreme Court, British Virgin Islands in 2022.

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Jonathan is intellectually very good and across the details on very complex cases.

Chambers UK Bar 2025

Jonathan is an excellent advocate on paper and on his feet.

Chambers UK Bar 2025

Very thorough in his analysis. Able to work through huge amounts of documentation and identify what matters and the key issues. Clearly very well prepared when it comes to cross examination and able to think quickly on his feet.

The Legal 500 UK Bar 2025

First class at drafting and building an argument. Very quick.

The Legal 500 UK Bar 2022

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