The Growing Thicket of Multi-Layered Procurement Liberalisation between WTO GPA Parties, as Evidenced in Post-Brexit UK

The World Trade Organisation Government Procurement Agreement (GPA) has created the most comprehensive plurilateral system for procurement-related trade liberalisation. However, there has been a proliferation of free trade agreements (FTAs) regulating public procurement liberalisation, including between GPA parties, which seek to bypass or go beyond the GPA on a bilateral basis, or with a more limited plurilateral remit. Such FTAs tend to follow a ‘GPA+’ approach to provide incremental trade liberalisation based on the substantive provisions of the GPA. However, there is a trend of substantive divergence between the GPA regulatory baseline and the FTA regulation of crucial issues, such as the national treatment obligation or access to remedies, including in FTAs involving the European Union or, recently, its former Member State, the UK. This creates a situation of potential conflict of treaty norms that has so far received limited attention. This article focuses on the resolution of conflicts between GPA and FTA substantive provisions under the 1969 Vienna Convention on the Law of Treaties, using the UK’s post-Brexit FTAs as a case study. It argues for a rationalisation of the system by extending the use of incorporation by reference of the GPA in FTAs involving GPA parties