Prof. Dr. Nikos Lavranos, Secretary-General of the European Federation for Investment Law and Arbitration (EFILA) and member of PIL Advisory Group, has commented on the recent judgment of the Court of Justice of the European Union in the Achmea case (Case C-284/16, Slowakische Republik v Achmea BV). The Court ruled that the arbitration clause in the BIT between the Netherlands and Slovakia has an adverse effect on the autonomy of EU law, and is therefore not compatible with EU law. In his critical comments published by Thomson Reuters’ Practical Law Arbitration Blog, Nikos argued inter alia that the ECJ ruling raised failed to make a distinction between ICSID and non-ICSID arbitration proceedings, while in the self-contained regime of the 1965 ICSID Convention, ICSID awards are automatically recognisable and enforceable in all 150 contracting parties to the ICSID Convention, without any review or interference by domestic courts. Dr. Lavranos also examines the potentially far-reaching implications of the judgment, including the issue of intra-EU BITs awards that have already been paid to investors. He addresses the issues of whether EU member states may be entitled to recoup payments already made to investors pursuant to arbitral awards, on the ground that the whole arbitration procedure was based on an ISDS provision, which ab initio was incompatible with EU law.