Brexit: Devolution and legislative consent

Legislative consent is a fundamental part of the territorial constitutional arrangements of the United Kingdom. The self-denying ordinance of the UK Parliament that it will normally only legislate with regard to devolved matters with the consent of the devolved legislature is a non-legal constitutional constraint. It helps to protect and preserve autonomous spheres of constitutional authority with regard to devolved legislatures and their related institutions.

The withdrawal of the UK from the European Union poses significant challenges to the existing devolution settlements in Scotland, Wales and Northern Ireland. Several key pieces of legislation, deemed necessary by the UK Government to deliver its policy of withdrawing the UK from the EU, have significant implications for the powers of the devolved legislatures and executive bodies.

The first such piece of legislation was the European Union (Notification of Withdrawal Act) 2017, which was necessary to commence the Article 50 withdrawal process. The litigation that gave rise to the requirement for that Act also clarified the role of legislative consent in the UK constitution. In particular, it highlighted its limitations as a mechanism by which devolved legislatures could influence the Brexit process.

Several Brexit framework Bills will, among other things, make significant modifications to the powers of the devolved legislatures and executive bodies. Those Bills, especially the European Union (Withdrawal) Bill 2017-19 (EUW Bill), the Trade Bill 2017-19, and the anticipated European Union (Withdrawal Agreement and Implementation) Bill, are understood to include, or be very likely to include, provisions that engage the legislative consent procedures of the respective devolved legislatures.

Both the Scottish and Welsh Governments have indicated that they will withhold legislative consent for the EUW Bill and the Trade Bill. They are concerned that the provisions in those Bills would diminish the existing competencies of the devolved legislatures and executives.

The Scottish and Welsh Governments have introduced “Continuity” Bills before their respective legislatures. These Bills seek pre-emptively to protect devolved institutions against the changes that the EUW Bill in particular, would make to the Scotland Act 1998 and the Government of Wales Act 2006. Whether these Bills themselves fall within the legislative competence of the devolved Parliaments is itself a contentious constitutional question.

Were legislative consent to be withheld in relation to one or more of the relevant Brexit framework Bills, the UK Government would not be prevented, legally, from presenting the legislation for Royal Assent. To do so, however, would be a constitutionally unprecedented course of action, the Government having explicitly acknowledged that the convention applies to those Bills.