This article examines how the Euro-crisis and responses to it have affected the horizontal relations of power between the EU Member States. It is argued that, whereas the EU institutional system had been designed since its foundation to strike a balance between state equality and state power, the Euro-crisis and the responses to it have increasingly upset this balance. A dynamic of inter-state domination is evidenced by the intergovernmental modes of governance within the European Council, as well as by the legal reforms in salient areas such as economic assistance, financial stabilisation and banking resolution, which have entrenched asymmetries between the states. In this article, it is argued that this dynamic constitutes a worrying development, given the anti-hegemonic nature of the EU integration project, and shows how intergovernmentalism paradoxically caters for powerful Member States. The article ends by considering options for institutional reforms, cautioning against the proposal to parliamentarise the EU and emphasising the potential of a new separation-of-powers system to restore a proper balance between the Member States.