The Sewel Convention and legislative consent

The Sewel Convention is a constitutional convention under which the United Kingdom Parliament will “not normally” legislate on devolved matters without the consent of the relevant devolved legislature.

Consent is granted via a Legislative Consent Motion (LCM) which is tabled, debated and voted on in either the Scottish Parliament, Senedd (Welsh Parliament) or Northern Ireland Assembly. This follows publication of a Legislative Consent Memorandum in which the relevant devolved government assesses the impact of planned UK legislation.

Origins and development

The principle behind the Sewel Convention predates devolution to Scotland in 1999. Between 1921 and 1972, a similar convention operated in Northern Ireland, where the UK Parliament would legislate on “transferred” (devolved) matters only by invitation from – or with the consent of – the devolved Parliament of Northern Ireland which existed between 1921 and 1972.

The term “Sewel Convention” was first used in 1999 and named after Lord Sewel, the Scottish Office Minister who described the principle during the passage of the Scotland Bill. The first Legislative Consent Motion was passed by the Scottish Parliament in June 1999.

The Convention was later adopted by the National Assembly for Wales (now the Senedd) and the Northern Ireland Assembly. Each legislature developed its own procedures for handling LCMs.

Legal status and justiciability

Although recognised in statute, the Sewel Convention is not legally binding and cannot be enforced by the courts.

The Scotland Act 2016 and Wales Act 2017 include provisions recognising the Sewel Convention, but the Supreme Court confirmed in the Miller I case that it remained a political convention, binding “in honour only”.

Application and scope

The Sewel Convention applies when UK legislation affects devolved matters, alters the legislative competence of devolved legislatures, or changes the executive powers of devolved ministers. UK government departments must assess whether proposed legislation engages the Convention and consult the devolved governments accordingly. A Cabinet committee called the Parliamentary Business and Legislation (PBL) Committee oversees this process.

The procedure for Private Members’ Bills supported by the UK government is similar. The Convention does not apply to secondary legislation.

Legislative consent process

Each devolved legislature has its own procedures for considering Legislative Consent Motions. The responsible devolved minister tables a Legislative Consent Memorandum, which is referred to a committee for scrutiny. A vote on the subsequent Motion must take place before the final amending stage of the bill in the second House at Westminster. If consent is refused by a devolved legislature, the UK government may amend the bill, remove the relevant provisions, or proceed regardless.

Brexit and legislative consent

Before Brexit, refusals of legislative consent were rare. However, following the 2016 referendum on the UK’s membership of the European Union, the Sewel Convention became more contested. The Scottish Parliament withheld consent for the European Union (Withdrawal) Act 2018, and all three devolved legislatures refused consent for the European Union (Withdrawal Agreement) Act 2020. Despite this, both Acts were passed by the UK Parliament. Between 2018 and 2023, six Acts were passed without consent, five of which related to Brexit.

The UK Government argued that these were exceptional circumstances and therefore fell outside the “normal” scope of the Convention. The devolved governments criticised this approach, claiming it breached both the letter and spirit of the Convention.

Reform proposals

Several bodies have proposed reforms to strengthen the Sewel Convention. The Institute for Government has recommended clearer rules on when consent is required and greater UK parliamentary scrutiny. The House of Lords Constitution Committee has called for more transparency and engagement between legislatures. The Northern Ireland Assembly Committee on Procedures has suggested changes to improve the timeliness and clarity of the consent process.

In 2022, a Labour Party commission proposed making the Convention legally binding, although its 2024 manifesto pledged only to strengthen it through a new Memorandum of Understanding.

Other consent conventions

The UK Parliament also observes conventions when legislating in respect of other domestic and international bodies. These include the Crown Dependencies (Guernsey, Jersey and the Isle of Man), the British Overseas Territories, the Church of England and the Commonwealth Realms. In each case, the UK Parliament generally seeks consent before legislating, although the legal and constitutional basis varies.