'De facto or Implicit Treaty Amendments in European Union Law'

14 Jul 2025

The event was held at Erasmus University Rotterdam on 12–13 June 2025

Dr Roila Mavrouli, Lecturer at the School of Law, University College Cork, participated in the international conference De facto or Implicit Treaty Amendments in European Union Law, held at Erasmus University Rotterdam on 12–13 June 2025. The event was co-organised by Dr Luigi Lonardo (UCC) and Dr Menelaos Markakis (Erasmus University Rotterdam), with the support of the Erasmus Centre for Economic and Financial Governance and the Royal Irish Academy.

The conference brought together leading EU legal scholars and practitioners to explore the phenomenon of implicit or de facto Treaty amendments in EU law. It focused on how legal and institutional change may occur in practice—through soft law, secondary legislation, the case law of the Court of Justice, and institutional practice—and what this reveals about the evolution of EU constitutionalism.

This conference offered a valuable opportunity to engage critically with the EU’s evolving constitutional framework and reflect on the circumstances in which the EU Treaties are changed, without following the formal procedures contained therein (because the text itself is changed, or because the interpretation of a provision evolves, or because a new understanding of a Treaty provision or principle emerges).

Dr Mavrouli’s participation, and the resulting platform for future academic collaborations—including follow-up workshops—was made possible thanks to the generous support of the Head of Law Strategic Fund, which is gratefully acknowledged. This support also enabled the development and deepening of international research networks with institutions including the University of Luxembourg, Université Paris II Panthéon-Assas, Erasmus University Rotterdam, Princeton University, University of Essex and the European Commission.