Transition Time: 3 Options for Extending the Transition Period

11 Pages Posted: 25 Oct 2018

See all articles by Kenneth Armstrong

Kenneth Armstrong

University of Cambridge; Centre for European Legal Studies

Date Written: October 21, 2018


The draft Withdrawal Agreement creates a transition period which will end on 31 December 2020. During this period, the United Kingdom will cease to be a Member State of the European Union but will still comply with EU law pending the entry into force of a new UK-EU partnership agreement. It is becoming clear that the fixed end-point of 31 December 2020 is unrealistic to allow negotiations to reach a new partnership agreement. This is also significant because the UK considers that it is through a new economic relationship that a hard border on the island of Ireland will be avoided. In order to guarantee that no new frontier controls are introduced, the EU has insisted that a ‘backstop’ arrangement is written into a Withdrawal Agreement. The difficulties in defining this backstop risk jeopardising the conclusion of Article 50 negotiations, leading to a potential ‘No Deal’ Brexit. This working paper argues that a different approach to the transition period is needed and sets out three possibilities:

(1) an optional extension;

(2) an open or rolling transition with an exit mechanism;

(3) an extended transition and implementation facility.

The paper concludes that politically and legally, agreement on an extended transition and implementation facility has the potential to offer the necessary flexibility and certainty to finalise negotiations on a Withdrawal Agreement while creating sufficient time for new agreements on the future relationship to be negotiated and agreed.

Keywords: brexit, EU Withdrawal, Article 50, European Union, Withdrawal Agreement, No deal, No deal brexit, transition, transition period, implementation period

Suggested Citation

Armstrong, Kenneth, Transition Time: 3 Options for Extending the Transition Period (October 21, 2018). University of Cambridge Faculty of Law Research Paper No. 61/2018, Available at SSRN: or

Kenneth Armstrong (Contact Author)

University of Cambridge ( email )

Trinity Ln
Cambridge, CB2 1TN
United Kingdom

Centre for European Legal Studies ( email )

10 West Road
Cambridge, CB3 9DZ
United Kingdom


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