In the spring of 2005, the European Union was plunged into a state of crisis when two of the Union's founding members (France and the Netherlands) rejected the proposed EU Constitution in two separate referendums. In this article, it is argued that the 'no' votes in both countries, despite the support of mainstream political elites and the bulk of the media, should not be viewed with surprise. The article begins by examining the background debate to the referendums in both countries before considering the major issues that dominated the 'no' campaigns as well as the issues that motivated the two countries' electorates in their decisions to reject the EU Constitution. From here, the article examines the significance of the 2005 'no' votes in the current context within France and the Netherlands and argues that the clear polarization of the 'no' vote among those from socio-economically less well-off backgrounds is not only the sign of a further widening of the gap between mainstream political elites and their supporters with regard to European integration, but that in turn it is also having a significant impact at a party level in terms of the galvanization of Eurosceptic political parties - particularly the radical right. The article concludes with the argument that 2005 has contributed to the growing salience of Euroscepticism within both countries, which in the context of the crisis in the eurozone is likely to lead to further re-evaluation of the European project among political elites. © 2012 Blackwell Publishing Ltd.