Relais actors revisited: conditional rapporteur bias in EU legislative bargaining

As the sole negotiators representing the European Parliament (EP) in interinstitutional bargaining, rapporteurs play a pivotal role in shaping legislative outcomes. However, the extant qualitative evidence has shown that they do not always perform their duty to defend the EP’s official mandate. Instead, they may leverage their influence to align outcomes with the preferences of their party groups. Drawing on an original dataset that captures the preferences of the EP’s political groups across 31 legislative dossiers from the Ninth Parliament, this study investigates the conditions under which rapporteurs bias legislation. We test the impact of three moderators, namely the influence of the Council and the Commission, as well as the impact of internal EP support for the rapporteur’s preferences. Our findings reveal that rapporteurs indeed bias legislation in favour of their party groups, but only when they can count on the support of the Council. We also find some evidence suggesting that slack may be enabled by the Commission, but little indication that internal alliances play a role. This article advances our understanding of the dynamics between key institutional actors in shaping EU legislation and provides, to our knowledge, the first large-n conditional validation of the relais actor thesis.