Thomas Sebastian > Chambers of Tim Ward QC and Philip Moser QC > London, England > Lawyer Profile

Chambers of Tim Ward QC and Philip Moser QC
Monckton Chambers
Thomas Sebastian photo


Thomas has extensive experience advising and representing sovereigns and corporations in disputes under international treaties. He has appeared before tribunals established under bilateral investment treaties, WTO panels and the WTO’s Appellate Body and has acted in over 20 treaty disputes for states as varied as Poland, Columbia, Thailand, India and South Africa. Thomas also acts in international commercial arbitrations. Thomas is one of the handful of UK barristers who is also called to the Indian bar and is, therefore, well-placed to act in disputes involving an Indian element.


Called 2012. Thomas was previously a Senior Associate at Allen & Overy’s International Arbitration Group in London (2009-2012) and a counsel at the Advisory Centre on WTO Law, Geneva (2002-09). He transferred to the English Bar in September 2012 was taken on as a tenant at Monckton Chambers in February 2013 after a shortened period of pupillage.


BA, LLB (Hens) (NLSIU), BCL (Oxen), MPhil (Oxen).

Lawyer Rankings

London Bar > Public international law

(Leading Juniors) Ranked: Tier 3

Thomas SebastianMonckton ChambersOne of the most experienced, if not the most experienced, counsel on trade law issues in the UK, he is also excellent on investment treaty issues.

London Bar > International arbitration: counsel

(Leading Juniors) Ranked: Tier 3

Thomas SebastianMonckton ChambersVery responsive and always make himself available to discuss matters and turns work around promptly – his advice is comprehensive and accounts not only for the strict legal merits of the position, but also considers the broader strategic perspective of the case.

London Bar > Competition

(Leading Juniors) Ranked: Tier 3

Thomas SebastianMonckton ChambersSignificant expertise in competition disputes and gives high quality advice which is measured and considered; calm and composed and easy to deal with.

Asia Pacific - The English Bar > Commercial

(Leading Juniors) Ranked: Tier 2

Thomas SebastianMonckton ChambersHe is very responsive, and provides comprehensive advice that takes into account all aspects of the dispute.

Thomas Sebastian, a member of Monckton Chambers, is also called to the Indian Bar. He is well-versed in disputes arising under investment treaties and frequently handles international commercial arbitrations.

Asia Pacific - The English Bar > Set overview

Monckton Chambers‘ Thomas Sebastian is called to the Indian Bar and plays an active role in the local commercial disputes market. David Hockney is the senior clerk, supported by deputy John Keegan. Offices in: London.