National parliaments have the potential to serve as transmission belts between the European Union (EU) and their citizens. By publicly communicating EU issues, they can enhance the visibility, public accountability and ultimately the legitimacy of supranational governance. Not least since the Eurozone crisis, this task has become increasingly important in the ever more politicised context of EU integration characterised by public and partisan contestation. Against this background, the aim of the paper is to investigate the communication efforts of national parliaments in EU affairs and, in particular, to analyse the impact of the levels of contestation of EU issues both within the public and the parliamentary arena on their communication activities. In a nutshell, in how far has political contestation acted as a catalyst for parliamentary communication of EU affairs? Our data on plenary activities in seven EU parliaments from 2010 to 2013 reveals that political contestation in public opinion has a positive impact, while contestation within parliament may hamper communication of EU affairs.