The article analyzes the historical process of forming an economic and monetary union within the European Union. The institutional and legal, economic foundations of this process are considered and the accompanying problems and contradictions are revealed. It is shown that there are different scenarios for the formation of an economic and monetary union in relation to political integration. At the same time, the main problem lies in the different level of socio-economic development of the European Union member states and the ratio of supporters and opponents of European integration in the political space of the member states.