Achmea Upside Down: Role Reversal of Parties in Set-Aside Proceedings on Mixed Intra-EU Investment Arbitration

This article examines a notable ‘mixed’ intra-EU investment arbitration involving EU and Swiss investors against Poland. The state objected to jurisdiction based on the CJEU’s Achmea ruling, which found intra-EU investment arbitration incompatible with EU law. The tribunal rejected the objection but dismissed the claims on the merits, ordering the investors to bear all arbitration costs jointly. The case took a remarkable turn during set-aside proceedings in Sweden, initiated by the investors to annul the costs order, where both parties reversed their original jurisdictional positions. The Swedish Supreme Court clarified that the Achmea doctrine applies only to intra-EU disputes, not to investors from non-EU states. It overturned the Svea Court of Appeal’s annulment of the entire award and reinstated the tribunal’s costs decision for the Swiss investor alone. The case highlights questions about consistency in legal argumentation and the evolving landscape of intra-EU investment arbitration and related court proceedings in Europe.