Introducing the legislative priority rule: a constitutional compass for the Court

Abstract

The ambiguous nature of the internal market allows for EU legislative input on two tensions animating this field since its inception, those being how to divide power between the EU and Member States and how to reconcile the requirements of integration and regulation. The Court can sometimes struggle with accommodating such input with its Treaty interpretation, leading to further tension with the EU legislator. In the internal market for goods, however, it can rely on the Legislative Priority Rule to resolve disputes in a coherent, Treaty-compliant manner. Casting exhaustive EU legislation as the sole norm against which to assess national product measures, to the exclusion of Articles 34–36 of the Treaty on the Functioning of the European Union (TFEU), this longstanding Rule is, from one perspective, a simple procedural tool to establish the Court’s framework of reference. In reality, however, invoking (or excluding) the Rule can have a substantive and institutional dimension, as its application (or not) engages the relationships between national, secondary, and primary law and, by extension, the Member States, EU legislator, and Court. On the one hand, the Rule enforces EU primacy by pre-empting national competence in the presence of harmonization. On the other, by suspending direct application of Articles 34–35 TFEU, it also implies deference to the EU legislator, and indirectly to the Member States, which enjoy discretion to set standards and determine how power is shared. As a result, while Member States cannot avoid free movement obligations, they can defend national rules by reference to this EU standard to which they have contributed. There is in other words an alignment under the Rule between the dynamics of Exit and Voice, with the Court exercising boundary control to ensure compliance with primary law. It is on this basis that I have come to identify the Legislative Priority Rule as a sort of ‘constitutional compass’ to guide the distribution of power in the internal market for goods. Despite this key role, however, its existence and impact remain relatively unknown or at best ignored, reflecting a gap in understanding the Court’s toolbox for review and a failure to appreciate the role of secondary legislation in building a stable, Treaty-compliant regulatory system.