The author questions the influence of the creation of a single currency on the formation of European citizenship. Whereas the transnational dimension of such citizenship (which affects the citizen of one Member State residing in another) must be kept separate from the supra national dimension (which affects the relationship between the people and the public powers of the Union), he believes that the euro mainly concerns the second dimensions and that it marks the peak in the contradiction between the success of the European market (compared with the division in national markets) and the failure of the Union as an organised form of political cohabitation. The reasons would consist mainly in the shortsighted and irresponsible vision of the national political classes, interested in maintaining the image of a European bureaucracy or technocracy in order to continue gaining consensus without taking responsibility.