Professor Panos Koutrakos:

With regard to economic sovereignty, at the level of international economic law the obligations imposed on states and the European Union are not absolute. Even at that level there are exceptions. For example, since we are talking about services, the General Agreement on Trade in Services, GATS, which is a WTO agreement, imposes specific obligations on parties and of course the European Union is a party. At the same time there is a public policy exception, I believe it is in Article XIV. The obligations are not absolute and it does not necessarily follow that a unilateral restriction under EU law would be illegal under international economic law.