With the lingering Euro crisis, personalized competition for the Commission presidency, and a surge of Eurosceptic parties, the 2014 European Parliament elections took place against an unknown level of European Union politicization. How does this changing context affect the supply side of party competition on European issues in EP election campaigns? This article compares the 2014 and 2009 EP elections in two EU founding members with high electoral support for radical left and radical right Euroscepticism - France and the Netherlands. We study publically visible patterns of partisan mobilization in the written news media with semi-automated content analyses. The data indicate that visible party mobilization on EU issues was on average not significantly higher in 2014. While particularly mainstream and especially incumbent parties publically mobilize on European issues during both campaigns, the radical right's mobilization efforts have become more visible during the 2014 elections. Examining the temporal dynamics within electoral campaigns, we show that the Eurosceptic fringes exhibit significant contagion effects on the mainstream parties, but that the extent of this contagion was surprisingly lower in the 2014 campaign. As a result, the increasing EU politicization between the 2009 and 2014 electoral contests has not resulted in an enhanced and more interactive supply of partisan debate about Europe. (author's abstract)