He is admitted to practice in Ireland, England & Wales, and New York.
He has won some of the largest and most high-profile arbitrations in the world, including two cases accorded “international arbitration team of the year” by Legal Business. He has also been voted as an “MVP” for international arbitration by Law 360 and is recognised as a leader in his field by multiple directories, which describe him as “a superb advocate”. His clients note: “He's excellent and has a great way of understanding complex issues and making them commercially understandable for the lay person. We rate him highly." (Chambers UK 2025)
David has an undefeated track record of success in investor-state arbitration, acting both for investors and for states over the last two decades, including in several multi-billion euro disputes. Beyond these cases, David has also obtained favourable awards or settlements for clients in dozens of commercial arbitrations under the arbitral rules of the ICC, LCIA, HKIAC, SIAC, ICDR, AAA and UNCITRAL.
David is licensed to practice EU law and is highly experienced in that field. This enables him to advise clients in arbitration and litigation matters with an EU law element. For example, he currently acts for renewable energy investors in multiple enforcement proceedings involving both EU law and the ICSID Convention. This includes prevailing for investors in the leading judgment of the U.S. Circuit Court of Appeals on enforceability of intra-EU arbitration awards under the ICSID Convention and the U.S. Foreign Sovereign Immunities Act. David also represented those investors in successfully opposing Spain’s petition for certiorari before the US Supreme Court (cert. denied in June 2026).
David has particular expertise in disputes relating to the renewable energy, telecoms and technology sectors.
David is a Band 1-ranked lawyer in Chambers UK 2027 for Investor-State Arbitration. Legal 500 ranks him as a Leading Partner for Public International Law.
