The European Parliament oversight of EU agencies through written questions

© 2015 Informa UK Limited, trading as Taylor & Francis Group. The reinforcement of the legislative and oversight powers of the European Parliament by virtue of successive treaty reforms over the last two decades has been in parallel with an expanding process of agency creation at the European Union (EU) level. While these two institutional developments entail major transformations of legislative–executive relations in the EU, the European Parliament oversight of EU agencies remains an underexplored topic of research. Based on an original dataset on parliamentary written questions overseeing EU agencies asked during the 2009–14 Legislature, the article analyses members of the European Parliament (MEPs) questioning activity overseeing EU agencies. The article argues that legislative oversight of agencies through written questions is driven by MEPs national party opposition status as well as by agency salience and size.