Accession to International Instruments as an EU Legality Constraint

When the EU becomes a party to an international legal instrument, whether bilateral or multilateral, that international agreement is incorporated automatically in the EU legal order and becomes a legality constraint within that legal order, due to the recognition, by EU law itself, of the precedence of those international commitments over secondary EU law. In the multilevel European legal space, agreements concluded by the EU also become a legality constraint for the Member States of the EU, even if they are not parties to the international instrument themselves. Ensuring compliance with the EU’s international obligations sets in motion the adoption of internal legislation to implement those international obligations or to repeal existing EU law measures that are inconsistent with them; and the Court of Justice of the European Union can review the compliance of EU secondary law (and Member State law) with the EU’s international agreements. However, the Court has self-limited this review power through the development of a doctrine on the limited direct effect of international agreements.