It is traditionally argued that the topic of European integration is rather absent or under-discussed in French political debate. In this context, it came as a surprise that the 2017 French presidential election turned into a 'referendum sur l'appartenance a l'Union' (Costa 2017). This article argues that after many presidential campaigns where Europe remained 'the elephant in the room', 2017 saw its settling as a clear line of cleavage between political parties, relegating the traditional left/right cleavage to a secondary position. The politicisation of socio-economic questions at European level also signalled a move away from the traditional value-based Eurosceptic grounds towards a will to shape the debate in the direction of a more social Europe.