Book Talk – ‘Constitutional Disintegration and Disruption: Withdrawal and Opt-Outs from the European Union’

Speaker/Author: Dr Oliver Garner, The City Law School

Chair: Timothy Lyons KC BL, Advocaat/Avocat Brussels Bar

Discussants: Prof Francesca Strumia, The City Law School & Dr Darren Harvey, King’s College London

Abstract

‘Constitutional Disintegration and Disruption: Withdrawal and Opt-Outs from the European Union’ by Oliver Garner (OUP 2025)

The United Kingdom's unprecedented withdrawal from the European Union in 2020 may be regarded as the first example of European 'disintegration'. This moment, however, was preceded by decades of 'disruption' as the UK, Ireland, and Denmark pursued opt-outs from the supranational constitutional order.

Constitutional Disintegration and Disruption: Withdrawal and Opt-Outs from the European Union provides the first comprehensive analysis of these two phenomena.

The book presents the European Union as an order that is legitimated by individuals playing a dual role as both nationals of Member States and citizens of the European Union; in turn, individuals are both democratic subjects and juridical objects within this order.

The EU Treaties have instituted a 'triptych' for the exercise of 'constituted constituent power' by these individuals: Article 49 TEU allowing accession, Article 48 TEU enabling amendment, and Article 50 TEU as a mechanism for the repatriation of power through withdrawal. Opt-outs are an iterative anomaly that have arisen through the retention of amendment power by representatives of Member State nationals. Reservations of constituent power have been operationalized in Protocols to the Treaties. By contrast, the withdrawal clause was proactively inserted into the Treaties as a sovereign right for Member State nationals subject to an orderly supranational procedure for the benefit of all EU citizens.

The book presents narratives of disruption and disintegration that provide comprehensive historical overviews of how opt-outs and withdrawal arose and developed.

Constitutional Disintegration and Disruption concludes with criticism of the consequences of these phenomena for individuals, and proposes reforms to the EU Treaties that would enable citizens to more fully realize their dual role in the European constitutional space.

About the speaker

Dr Oliver Garner is a Lecturer in Law at The City Law School, City St George's, University of London from September 2025. He previously held positions at the Bingham Centre for the Rule of Law, British Institute of International and Comparative Law and the Central European University Democracy Institute. He completed his LL.M. and Ph.D. at the European University Institute and holds a BA Jurisprudence from the University of Oxford. Oliver's fields of research are EU law and UK constitutional law and he teaches Public Law, EU Law, and Immigration Law in The City Law School. His first monograph 'Constitutional

Disintegration and Disruption: Withdrawal and Opt-Outs from the European Union' was published in May 2025 by Oxford University Press. He has published articles, book reviews, and editorials in the European Law Review, the Cambridge Yearbook of European Legal Studies, the International Journal of Constitutional Law, Perspectives on Federalism, Les Cahiers Portalis, and the European Journal of Legal Studies.