Penelope Nevill > Twenty Essex > London, England > Lawyer Profile

Twenty Essex

Work Department

  • Arbitration and mediation
  • Commercial Law
  • Constitutional, public and human rights law
  • Public international law


Penelope is a specialist in international law. Her practice focuses on disputes and transactional advice across a range of areas, including public international law, EU law, public law and human rights and commercial disputes raising questions of international and EU law.

She has appeared as counsel before the International Court of Justice, the European Court of Human Rights, the General Court of the EU and a United Nations Convention on the Law of the Sea (UNCLOS) Annex VII Tribunal, as well as the High Court, the Court of Appeal and the Supreme Court of England and Wales. In addition, Penelope regularly provides transactional advice to governments, the private sector and NGOs.

Most of Penelope’s work involves the interaction between the international, EU and national legal systems and different regimes under international and regional law. Having started her career as a litigation lawyer in New Zealand with leading firm Chapman Tripp, she has extensive and varied practice experience. In addition, Penelope has been a full-time academic at the University of Cambridge, teaching public international law, EU law and the law of armed conflict. She is currently a visiting lecturer at King’s College, London.


Qualified 2010. Barrister and solicitor of the High Court of New Zealand 1998; solicitor specialising in litigation (employment and general commercial) at Chapman Tripp Sheffield Young 1997-2001, Auckland; research fellow, Lauterpacht Centre for International Law, Cambridge 2002-05; fellow, Downing College, Cambridge 2005-10. Publications of note: ‘Sanctions: the Shifting Legal Landscape’ (with Sara Masters), Legal Week, 9 March 2012; ‘Relations Between International Courts and Tribunals’, with James Crawford, in Margaret Young ed, Regime Interaction in International Law (Cambridge University Press, 2012); ‘Treaty Interpretation and Troubled Treaty Regimes: The Case of International Investment Law’, in Marcel Szabo ed; ‘State Responsibility and the Law of Treaties’ (The Hague, Eleven International Publishing, 2010), 161; ‘Interest’, with Elihu Lauterpacht, in James Crawford, Alain Pellet and Simon Olleson (eds) (with the collaboration ofKate Parlett); ‘The Law of International Responsibility’ (Oxford, Oxford University Press, 2010); ‘The Treatment of Interest in International Awards’ [2007] 78 British Year Book of International Law 255.


  • American Society of International Law (Program Committee Member, ASIL Meeting 2018)
  • Attorney General’s Specialist Public International Law B Panel (from 1 March 2014)
  • International Law Association, British Branch


University of Auckland, New Zealand (BA, LLB(Hons)); Jesus College, University of Cambridge (LLM).

Lawyer Rankings

London Bar > Public international law

(Leading Juniors)Ranked: Tier 1

Penelope NevillTwenty Essex ‘Very quick and astute with a broad range of knowledge across areas. Willing to engage with any question no matter how big or small and always happy to get stuck into the laborious detail. Calm and diligent.’

London Bar > Administrative and public law (including elections)

(Leading Juniors)Ranked: Tier 4

Penelope NevillTwenty Essex