Expertise has been highlighted as a central source of power and legitimacy within the European Union system, and has been pointed to as one explanation of the relative influence of EU institutions in policy-making processes. This paper investigates such inter-institutional differences by asking: To what extent, and how, does expertise from the Commission influence the European Parliament’s positions? We explore this question by analysing the transfer of expertise from the Commission to the Parliament in the case of the Transatlantic Trade and Investment Partnership (TTIP). Our analysis finds clear differences in what type of expert knowledge the EP incorporated– as well as how they use expertise. In the beginning of the period analysed, the Commission’s expert input is broadly used by the EP and largely unquestioned. Some years later, there is much less reference to external expert and Commission sources and the EP is also much more critical, and explicitly questions conclusions that was supported two years earlier. In our final discussion, we propose that this change over time might be due to the politicisation of TTIP, and discuss how and why this is the case.
This is an Accepted Manuscript of an article published by Taylor & Francis available online: http://www.tandfonline.com/.