This paper discusses the role of the European Citizens’ Initiative (ECI) in redefining the discursive and legitimatory dimension of the public in the European Union. The ECI will enter into force in April 2012 as the most direct form of participatory democracy in the EU to date, giving EU citizens an institutional opportunity to set the agenda in the EU’s legislative process. Drawing on Habermas’ notion of postnational democracy and Bohman’s notion of transnational democracy, the paper interprets the ECI as an exercise in European demos construction. The ECI, it is argued, goes further than introducing a new institutional means to ameliorate the presumed democratic deficit in EU decision making. Seeing as the ECI requires transnational civil society mobilization, it actually creates an institutional incentive for the emergence of stronger ties in European civil society, which may have a profound impact not only on Europeans’ self-awareness as EU citizens, but also on more general notions such the democratic deficit, the community or collective identity deficit, the demos deficit, or – more broadly – a “public deficit” haunting the ongoing quest for democratizing the EU. This resonates well with arguments developed in transformationalist democratic theory. Postnational democratic theorists in the Habermasian tradition would emphasize the emergence of a European demos as the end product of democratic practice at the European level. Transnational democratic theorists like Bohman, on the other hand, would see an even more fundamental transformation of the democratic ideal, construing the ECI as an institutional embodiment of non-domination as opposed to the traditional understanding of democracy as popular sovereignty.