Brexit the Ultimate Opt-out: Learning the Lessons on Differentiated Integration

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Table of Contents: I. Introduction. – II. Conceptual confusion. - III. Learning the lessons on differentiated integration. – III.1. The advent of Brexit. – III.2. The challenge for the future. – IV. Conclusion.

Abstract: Historically, the use of differentiated integration mechanisms has been based on the idea of the widening and deepening of the European Union, necessitated by the enlargement of the bloc through the addition of Member State countries. The advent of Brexit means that we are in a rather different situation today, where the monodirectional march towards deeper, uniform integration between an ever increasing number of States is neither inevitable nor assured. The differences between all of the then 28 individual Member States in the pre-Brexit Union were multifarious. These differences have not disappeared along with the UK upon its exit from the Union. They still exist between the remaining 27 Member States and will likely increase in prominence as the European Union pursues its future path. Addressing those differences will require an alternative approach to uniform integration from the EU, it will require differentiated integration. This Article suggests that there are lessons to be learnt on differentiated integration from applying Brexit as a framework. The confusion surrounding differentiated integration as a concept, and the prominent role of the UK in availing itself of opportunities to utilise differentiated integration mechanisms, has led differentiated integration to be attributed to the UK as a form of British exceptionalism. Brexit is not just an opt-out but the ultimate opt-out, a form of flexibility sought from outside the European Union, consequent on a lack of wider acceptance of differentiated integration in terms of both legal permissiveness and extent as well as attitude within the Union. The maintenance of differences between the remaining Member States means that there needs to be increased open acceptance of the likely need for greater differentiated integration in the future.

Keywords: Brexit – differentiated integration – concept – opt-out – disintegration – integration.

European Papers, Vol. 7, 2022, No 3, pp. 1211-1227
2499-8249 - doi: 10.15166/2499-8249/608

* Senior Lecturer, City University of London,


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