Using a qualitative research methodology and relying on more than 15 interviews with EU, WTO and interest groups, the paper sheds new light to an underdeveloped research area. Theoretically, we point to the limitations of the Principal Agent (PA) approach in EU governance and adopt a transnational networks theory approach instead. Empirically, the paper demonstrates the cyclical nature of the relationship between the EU and the WTO in adopting and revising the Union’s public procurement Directives as well as the WTO’s Global Procurement Agreement (GPA). With the Commission playing a central role in framing the contours of the EU policy debate and representing the EU member-states in the revision of the GPA, the paper also highlights the enhanced role of the European Parliament (EP) in reforming the EU policy agenda on procurement policy.