With the passage of the Wales Act 2017, the Senedd (or Welsh Parliament) joined the Scottish Parliament and Northern Ireland Assembly in following what is known as the “reserved powers” model of devolution, in that everything not specifically set out in statute as reserved to Westminster is assumed to be devolved.
Three separate Library Briefing Papers have looked at which matters are devolved to Wales, Scotland and Northern Ireland. The focus of this paper, however, is which decisions are still taken by the UK Parliament and Government.
While some reserved matters are common to all three devolved legislatures, such as the Crown, defence and foreign affairs, others are not. In Northern Ireland, for example, the ability to set income tax is reserved to the UK Parliament but, to varying degrees, devolved in Scotland and Wales. The fact that the extent of matters reserved to Westminster varies in Scotland, Wales and Northern Ireland is partly a reflection of each territory’s distinct history and governance.
The former Supreme Court President Lady Hale has observed that reserved matters have “no common characteristic” but rather “a common theme”, including areas which are affected by the UK’s “treaty obligations and matters that are designed to ensure that there is a single market within the United Kingdom for the free movement of goods and services”.
The number of reserved matters has also been reduced over time, most extensively in the case of Scotland, but also in Wales and Northern Ireland. There are only a few examples of powers moving in the other direction, for example Antarctica was specifically reserved in 2012, as was state aid in 2020. Some reserved matters – ie the ability to hold an independence referendum in Scotland – have been temporarily devolved.
After providing some historical background, this paper looks at, in turn, reserved matters in Scotland, Wales and Northern Ireland, before examining the role of the Supreme Court in determining the precise boundary between devolved and reserved matters in those three parts of the UK.
The paper concludes with an illustrative list of reserved matters in Scotland, Wales and Northern Ireland, as well as relevant UK departmental responsibility for each.