ABSTRACT – This contribution examines the main legal issues raised by the EU-Mercosur package, comprising the Partnership Agreement (EMPA) and the interim Trade Agreement (iTA), in light of the European Parliament’s recent referral to the Court of Justice. It discusses the bifurcation of the agreement, the rebalancing mechanism and the precautionary principle, before considering the provisional application of the iTA, the absence of investment protection provisions, and the position accorded to sustainable development. The contribution argues that the EU-Mercosur package provides an important test case for the EU’s treaty-making practice in the aftermath of Opinion 2/15.