The hearing took place on 12 June 2026. The case was handled by partner Mirjam van de Hel-Koedoot throughout the proceedings before the District Court and the Court of Appeal and is now before the Supreme Court, with Loyens & Loeff acting together with cassation counsel from Linklaters.

The proceedings concern the question of whether a Dutch court may intervene in an arbitration seated in the United Kingdom by ordering the investor to cooperate in the termination of the arbitration. The request is based on the premise that such proceedings would be incompatible with the Court of Justice of the European Union’s (CJEU) Achmea case law.

The case raises significant issues at the intersection of international arbitration, EU law and public international law. In particular, it examines the scope and implications of the CJEU’s case law on pending intra-EU investment arbitration, with a focus on:

  • the competence-competence principle;
  • the primacy of the courts of the seat of arbitration in reviewing jurisdictional questions;
  • the limited scope for judicial intervention in ongoing arbitrations, as well as the distinction between preventive intervention and ex post review at the enforcement or set aside stage; and
  • the legal position of investors seeking protection for investments made prior to the termination of the relevant intra-EU investment treaties. 

The Advocate General is expected to deliver her opinion in October 2026.
  
This case highlights our expertise in complex, high stakes disputes involving investment treaty arbitration, sovereign states, and the evolving interplay between EU law and international dispute resolution.