‘Retained EU law’: issues for the Withdrawal Agreement Bill

Publications / Briefings

‘Retained EU law’: issues for the Withdrawal Agreement Bill

23 May 2019

Coming on top of the controversial introduction of the concept of 'retained EU law' in the EU (Withdrawal) Act 2018, the provisions for an implementation / transition period in the UK-EU Withdrawal Agreement pose challenges for UK law that the promised Withdrawal Agreement Bill will need to address, including through amendments to the 2018 Act.

In this May 2019 paper, Swee Leng Harris – Head of Policy and Public Affairs at The Legal Education Foundation, and a member of the Bingham Centre's Expert Working Group on the EU (Withdrawal) Bill and the Rule of Law – first considers 'retained EU law' as a new category of UK law in terms of legal and constitutional status. The paper then makes observations about the constitutional and legal significance of implementation of the Withdrawal Agreement treaty in the promised Withdrawal Agreement Bill (WAB). Finally, the paper identifies necessary amendments to the EU (Withdrawal) Act 2018 (EU(W)A) to accommodate an implementation / transition period and to ensure legal certainty on retained EU law in UK law.

The paper draws a number of conclusions regarding retained EU law and legislative changes needed to accommodate an implementation / transition period and promote legal certainty:

Retained EU law needs to be understood in the round, including the constitutional provisions for retained EU law in the EU(W)A, changes made to retained EU law through secondary (or delegated) legislation, and other primary Brexit-related legislation affecting retained EU law.
The WAB will likely replicate the effect of the European Communities Act 1972 to apply EU law in the UK for the implementation / transition period.
EU law will develop and change during the implementation / transition period, and the WAB will need to enable those changes in EU law to be reflected in UK law.
The WAB should also amend the EU(W)A so that new or modified EU laws that apply in the UK through the WAB during implementation / transition form part of retained EU law.
Consequential amendments will be needed to enable retention of EU law under sections 2 and 4 of the EU(W)A if the ECA is to be repealed on exit day (at the beginning of the implementation / transition period) while the snapshot of EU law is to be taken on 'retention day' (at the end of the implementation / transition period).

The paper builds on the author's April 2018 paper 'Legislating for transition / implementation: implications for the EU (Withdrawal) Bill', also published by the Hansard Society, and develops the issues/arguments raised therein.

Latest / Highlights

News / Parliament Matters Bulletin: What’s coming up in Parliament this week? 20-24 October 2025

MPs will focus on the Bill to implement the UK–Mauritius Treaty transferring sovereignty over the Chagos Islands, the Sentencing Bill, and the Renters’ Rights Bill which is expected to be sent for Royal Assent. They will also discuss Scottish devolution and Black History Month, while the Northern Ireland Secretary gives evidence on the Windsor Framework and the legacy of the Troubles. In the Lords, the new Select Committee to consider the assisted dying bill begins its work. Peers will also examine the Planning and Infrastructure Bill, the Fraud Recovery Bill, and the Deprivation of Citizenship Orders Bill. They will hear from the Bank of England Governor, and consider the proposed suspension of former Lord Speaker, Baroness D’Souza.

News / Parliament’s spying scandal: Why was the China case dropped? - Parliament Matters podcast, Episode 110

It’s been a tumultuous week in Westminster, with three ministerial statements on the China spying case and fresh questions about the collapse of charges against two alleged spies. We are joined by Cambridge public law expert Professor Mark Elliott to untangle the legal and political fallout, from espionage claims inside MPs’ offices to confusion over whether China was ever designated an “enemy state.” We also explore looming government challenges — the Budget, Afghan data leak, local election setbacks — and the membership of the new Select Committee to consider the assisted dying legislation in the House of Lords. Please help us by completing our Listener Survey. It will only take a few minutes.

News / Former Prime Ministers: The role of Parliament in life after No 10 - Parliament Matters podcast, Episode 109

In this episode, we speak with Peter Just, author of a new book, Margaret Thatcher: Life After Downing Street. Peter explores how Thatcher reinvented herself after her departure to maintain her status as an international figure, and how she remained a parliamentary thorn in John Major’s side. We also compare her parliamentary afterlife with that of other Prime Ministers, and consider the value that former leaders can bring to the institution of Parliament. Please help us by completing our Listener Survey. It will only take a few minutes.

Briefings / Assisted dying - The Terminally Ill Adults (End of Life) Bill: Rolling news

Stay informed with updates and analysis on the Terminally Ill Adults (End of Life) Bill as it moves through Parliament. Learn about the debates, procedures, decisions, and key milestones shaping the assisted dying legislation.

News / What are the Usual Channels? A short history of Westminster whipping - Parliament Matters podcast, Episode 108

In this episode, we talk to political journalist Seb Whale about his new book, The Usual Channels, which reveals the hidden world of Westminster’s whips. Seb charts how party discipline has evolved – from the stormy politics of the 1970s and the Maastricht battles of the 1990s to the legendary “black book,” the Brexit showdowns and the short-lived Liz Truss premiership. He explains how the whips’ office has adapted to a modern Parliament – especially with the influx of women MPs – and why, even today, whips still wield decisive influence over MPs’ careers and remain indispensable despite the pressures of contemporary politics. Please help us by completing our Listener Survey. It will only take a few minutes.