'Leading candidates' competed for the European Commission Presidency in the campaign for the European elections in May 2014. This element of political contestation poses a challenge to the Union's institutional design. This work investigates to what extent competing 'leading candidates' enhances the process of deliberation and party contestation and thus strengthen the role of European Parliament (EP) party groups. In light of the example of the 'Progressive Alliance of Socialists and Democrats' and its 'leading candidate' Martin Schulz, it is shown that the election campaign did strive to be EU-wide. However, Schulz's influence on internal party cohesion and coalition formation remained limited. Therefore the influence of an elected 'leading candidate' is regarded as a symbolic act, which could deepen the relationship between the EP and the Commission as well as strengthen the democratic and political standing of both institutions vis-?-vis the European Council.