Withdrawal from mixed agreements under EU law: the case of the Energy Charter Treaty

This article argues that under EU law, both the EU and the Member States can independently from each other withdraw from a multilateral agreement such as the Energy Charter Treaty. While loyalty obligations may require both the EU and the Member States to closely cooperate their actions under a mixed agreement, this does not ultimately prevent them from taking the decision to withdraw. The autonomous nature of EU law, following Opinion 1/19, does not allow Member State decision-making to prevent the EU from taking decisions within EU competence. Similarly, as the Court maintains that under EU law the EU and the Member States are only ratifying those parts of the agreement that fall within their competence, Member States are entitled to cease exercising their powers through withdrawal. This power to withdraw unilaterally is, however, not without complications. First of all, it may affect the ability of the others to remain party to the ECT under EU law. Second, where not all Member States and the EU withdraw, ‘incomplete mixity’ raises several complicated questions under international law, in particular in relation to international responsibility and ISDS. Coordinated withdrawal by all Member States and the EU is therefore the preferable policy option