Political parties seek information about public preferences to determine how much they need to change their policies as elections approach. We argue that opposition parties can use European parliamentary election results to inform themselves about public preferences. When opposition parties lose votes at the European level, they can use this information to infer that public opinion has shifted away from the party and change their national policy strategies. We also argue that not all European elections are the same and that parties should be more responsive to those European elections that are more informative about public preferences. Empirical results from 14 European Union (EU) member countries show that opposition parties use European election results and change their positions (a) when the turnout levels between national and European elections are similar and (b) when the European election is close in time to the upcoming national election.