Professor Hestermeyer is a leading authority on international trade law and public international law. He has worked as specialist adviser to the House of Lords EU Select Committee, advising on the law of treaties and in particular free trade agreements, and as specialist adviser to the House of Lords EU Foreign Affairs Sub-Committee, working on questions of trade law related to Brexit. In the past, he advised an EU Member State on the public international law aspects of a project on nuclear non-proliferation and a company on prompt release of a ship and the liberation of the crew. Currently he advises an International Organization in Latin America on the law of international organizations.

Professor Hestermeyer has published widely on international law, including international trade law. Currently he is the general co-editor of the Brill Commentaries on World Trade Law. Professor Hestermeyer also regularly teaches trade law for the Department of International Trade / Department of Business and Trade.

Professor Hestermeyer is a renowned expert on EU law. Before joining academia, he worked as a Référendaire at the Court of Justice of the European Union. He has since advised the House of Lords EU Select Committee and the House of Lords EU Foreign Affairs Sub-Committee on matters of treaty law, on EU Free Trade Agreements and on legal questions of Brexit, having been named as Specialist Adviser. Professor Hestermeyer publishes widely on EU law, most recently on the Court of Justice’s case law after Achmea and the principle of autonomy of EU law.