Devolved, reserved and excepted matters in the context of Constituent country of the UK

The Parliament of the United Kingdom of Great Britain and Northern Ireland is the supreme legislative body of the United Kingdom, and may also legislate for the Crown Dependencies and the British Overseas Territories. Since 1999, varying degree of powers have been devolved to the devolved national parliaments of Northern Ireland, Scotland, and Wales. Each devolved parliament has different devolved powers, with Scotland being the most powerful amongst the three devolved parliaments. The central UK Parliament retains the power to legislate in reserved matters, including broadcasting, defence, and currency.

It meets at the Palace of Westminster in London. Parliament possesses legislative supremacy and thereby holds ultimate power over all other political bodies in the United Kingdom and the Overseas Territories. While Parliament is bicameral, it has three parts: the sovereign, the House of Lords, and the House of Commons. The three parts acting together to legislate may be described as the King-in-Parliament. The Crown normally acts on the advice of the prime minister, and the powers of the House of Lords are limited to only delaying legislation.

Since 1922, the United Kingdom has been made up of four countries: England, Scotland, Wales (which collectively make up Great Britain) and Northern Ireland (variously described as a country, province, jurisdiction or region). The UK prime minister's website has used the phrase "countries within a country" to describe the United Kingdom.

Although the United Kingdom is a unitary sovereign state, it contains three distinct legal jurisdictions in Scotland, England and Wales, and Northern Ireland, each retaining its own legal system even after joining the UK. Since 1998, Northern Ireland, Scotland, and Wales have also gained significant autonomy through the process of devolution. The UK Parliament and UK Government deal with all reserved matters for Northern Ireland, Scotland, and Wales, but not in general matters that have been devolved to the Northern Ireland Assembly, Scottish Parliament, and Senedd. Additionally, devolution in Northern Ireland is conditional on co-operation between the Northern Ireland Executive and the Government of Ireland (see North/South Ministerial Council) and the British Government consults with the Government of Ireland to reach agreement on some non-devolved matters for Northern Ireland (see British–Irish Intergovernmental Conference). England, comprising the majority of the population and area of the United Kingdom, does not have its own devolved government, and remains fully the responsibility of the United Kingdom Parliament centralised in London. In July 2025, the council of the English county of Cornwall backed a motion calling for Cornwall to be regarded as the UK's fifth nation.

The Scottish Parliament (Scottish Gaelic: Pàrlamaid na h-Alba [ˈpʰaːrˠl̪ˠəmɪtʲ nə ˈhal̪ˠapə]; Scots: Scots Pairlament) is the devolved, unicameral legislature of Scotland. It is located in the Holyrood area of Edinburgh, and is frequently referred to by the metonym ''Holyrood''. It is a democratically elected body and its role is to scrutinise the Scottish Government and legislate on devolved matters that are not reserved to the Parliament of the United Kingdom.

The Scottish Parliament comprises 129 members known as Members of the Scottish Parliament (MSPs), elected for five-year terms under the regionalised form of Additional-member system (MMP): 73 MSPs represent individual geographical constituencies elected by the plurality (first-past-the-post) system, while a further 56 are returned as list members from eight additional member regions. Each region elects seven party-list MSPs. Each region elects 15 to 17 MSPs in total. The most recent general election to the Parliament was held on 6 May 2021, with the Scottish National Party winning a plurality.

Welsh devolution is the transfer of legislative powers for self-governance to Wales by the Parliament of the United Kingdom. The current system of devolution began following the enactment of the Government of Wales Act 1998, with the responsibility of various devolved powers granted to the Welsh Government rather than being the responsibility of the Government of the United Kingdom.

Wales was conquered by England during the 13th century, with the Laws in Wales Acts 1535 and 1542 applying English law to Wales and incorporating it into England (survives as the England and Wales legal jurisdiction), and later into Great Britain and the United Kingdom. A rise in Welsh nationalism and political movements advocating for Welsh autonomy became more prominent in the late nineteenth century. The devolution of some administrative responsibilities began in the early twentieth century, as well as the passing of laws specific to Wales. Since World War II, various movements and proposals have advocated different models of Welsh devolution.

The Welsh Government (Welsh: Llywodraeth Cymru, pronounced [ɬəˈwɔdraːɨθ ˈkəmrɨ]) is the devolved government of Wales. It consists of cabinet secretaries and ministers. The government is led by the first minister, usually the leader of the largest party in the Senedd (Welsh Parliament; Welsh: Senedd Cymru), who selects ministers with the approval of the Senedd. The government is responsible for tabling policy in devolved areas (such as health, education, economic development, transport and local government) for consideration by the Senedd and implementing policy that has been approved by it.

The current Welsh Government is a Labour minority administration, following the 2021 Senedd election. It is led by Eluned Morgan who has been the first minister of Wales since August 2024.

The Parliament of the United Kingdom of Great Britain and Northern Ireland is the supreme legislative body of the United Kingdom, and may also legislate for the Crown Dependencies and the British Overseas Territories. Since 1999, varying degrees of powers have been devolved to the national parliaments of Northern Ireland, Scotland, and Wales. Each devolved parliament has different devolved powers, with Scotland being the most powerful amongst the three devolved parliaments. The central UK Parliament retains the power to legislate in reserved matters, including broadcasting, defence, and currency.

It meets at the Palace of Westminster in London. Parliament possesses legislative supremacy and thereby holds ultimate power over all other political bodies in the United Kingdom and the Overseas Territories. While Parliament is bicameral, it has three parts: the sovereign, the House of Lords, and the House of Commons. The three parts acting together to legislate may be described as the King-in-Parliament. The Crown normally acts on the advice of the Prime Minister, while the House of Lords’ powers are generally limited to delaying legislation.