The

Parliament of the United Kingdom 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. It meets at the Palace ...

currently has 650 parliamentary

constituencies An electoral (congressional, legislative, etc.) district, sometimes called a constituency, riding, or ward, is a geographical portion of a political unit, such as a country, state or province, city, or administrative region, created to provi ...

across the constituent countries (

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...

Wales Wales ( ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by the Irish Sea to the north and west, England to the England–Wales border, east, the Bristol Channel to the south, and the Celtic ...

, and

Northern Ireland Northern Ireland ( ; ) is a Countries of the United Kingdom, part of the United Kingdom in the north-east of the island of Ireland. It has been #Descriptions, variously described as a country, province or region. Northern Ireland shares Repub ...

), each electing a single member of parliament (MP) to the

House of Commons The House of Commons is the name for the elected lower house of the Bicameralism, bicameral parliaments of the United Kingdom and Canada. In both of these countries, the Commons holds much more legislative power than the nominally upper house of ...

by the

plurality Plurality may refer to: Law and politics * Plurality decision, in a decision by a multi-member court, an opinion held by more judges than any other but not by an overall majority * Plurality (voting), when a candidate or proposition polls more ...

(

first-past-the-post First-past-the-post (FPTP)—also called choose-one, first-preference plurality (FPP), or simply plurality—is a single-winner voting rule. Voters mark one candidate as their favorite, or First-preference votes, first-preference, and the cand ...

) voting system, ordinarily every five years.

Voting Voting is the process of choosing officials or policies by casting a ballot, a document used by people to formally express their preferences. Republics and representative democracies are governments where the population chooses representative ...

last took place in all 650 of those constituencies at the United Kingdom general election on 4 July 2024. The number of seats rose from 646 to 650 at the 2010 general election after proposals made by the boundary commissions for England, Wales, and Northern Ireland (the Fifth Periodic Review of Westminster constituencies) were adopted through statutory instruments. Constituencies in Scotland remained unchanged, as the

Boundary Commission for Scotland In the United Kingdom, the boundary commissions are non-departmental public bodies responsible for determining the boundaries of Constituencies of the Parliament of the United Kingdom, parliamentary constituencies for elections to the House of Co ...

had completed a review just before the 2005 general election, which had resulted in a reduction of 13 seats.

Primary legislation Primary legislation and secondary legislation (the latter also called delegated legislation or subordinate legislation) are two forms of law, created respectively by the legislative and executive branches of governments in representative democ ...

provides for the independence of the boundary commissions for each of the four parts of the UK, the number of seats for each of the countries, permissible factors to use in departing from any old boundaries, and a strong duty to consult. The Fifth Review was governed by the

Parliamentary Constituencies Act of 1986 The Parliamentary Constituencies Act 1986 (c. 56) is an Act of Parliament (United Kingdom), act of the Parliament of the United Kingdom. It is the legislation defining the constitution and work of the four Boundary commissions (United Kingdom) ...

. Under the

Parliamentary Voting System and Constituencies Act 2011 The Parliamentary Voting System and Constituencies Act 2011 (c. 1) is an act of the Parliament of the United Kingdom that made provision for the holding of a referendum on whether to introduce the Alternative Vote system in all future general e ...

, as amended by the

Parliamentary Constituencies Act 2020 The Parliamentary Constituencies Act 2020 (c. 25) is an Act of parliament, Act of the Parliament of the United Kingdom. It amends the regulations underpinning the parliamentary boundary review process as set out under the Parliamentary Constitue ...

, the number of MPs is now fixed at 650. The Sainte-Laguë formula method is used to form groups of seats split between the four parts of the United Kingdom and the English regions (as defined by the

NUTS 1 statistical regions of England International Territorial Level (ITL) is a geocode Standardization, standard for referencing the subdivisions of the United Kingdom for statistical purposes, used by the Office for National Statistics (ONS). Between 2003 and 2021, as part of the ...

Overview

The table below gives the number of eligible voters broken down by constituent country, including the average constituency size in each country. As of 2023, every recommended constituency must have an electorate as at 2 March 2020 that is no smaller than 69,724 and no larger than 77,062. The exceptions to this rule are five 'protected' constituencies for island areas: Orkney and Shetland,

Na h-Eileanan an Iar The Outer Hebrides ( ) or Western Isles ( , or ), sometimes known as the Long Isle or Long Island (), is an island chain off the west coast of mainland Scotland. It is the longest archipelago in the British Isles. The islands form part ...

, Ynys Mon, and two constituencies on the

Isle of Wight The Isle of Wight (Help:IPA/English, /waɪt/ Help:Pronunciation respelling key, ''WYTE'') is an island off the south coast of England which, together with its surrounding uninhabited islets and Skerry, skerries, is also a ceremonial county. T ...

. These consequently have smaller electorates than the lower limit for other constituencies.

Geographical size of constituencies

As the number of electors in each constituency is similar, the constituencies themselves vary considerably in area, ranging in 2019 from Ross, Skye and Lochaber, which occupies a sixth of Scotland, to the densely-populated London constituency of

Islington North Islington North is a United Kingdom constituencies, constituency in Greater London established for 1885 United Kingdom general election, the 1885 general election. It has been represented in the House of Commons of the United Kingdom, House of C ...

Parliamentary constituencies in the United Kingdom

Size of electorate in each United Kingdom house of commons constituency 2023

As of the 2024 election there are 543 constituencies in England, 32 in Wales, 57 in Scotland and 18 in Northern Ireland.

England

The "Region" of the table refers to the NUTS 1 statistical region of England, which coincides with the former

European Parliament constituency Member of the European Parliament, Members of the European Parliament (MEPs) are Elections in the European Union, elected by the population of the Member state of the European Union, member states of the European Union (EU). The European Elect ...

in which the constituency was included until 31 January 2020.

Scotland

Wales

Northern Ireland

Recent boundary reviews

Following the abandonment of the Sixth Periodic Review (the 2018 review), the

Boundary Commissions A boundary commission is a legal entity that determines borders of nations, states, constituencies. Notable boundary commissions have included: * Afghan Boundary Commission, an Anglo-Russian Boundary Commission, of 1885 and 1893, delineated the no ...

formally launched the 2023 Review on 5 January 2021 and published their final proposals on 28 June 2023. ''See

2023 review of Westminster constituencies The 2023 review of Westminster constituencies was the most recent cycle of the process to redraw the constituency map for the House of Commons of the United Kingdom. The new constituency boundaries were approved by the Privy Council on 15 Nov ...

and List of United Kingdom Parliament constituencies (2024–present) by region for further details.''

Summary of main boundary changes for the 2024 election

– Lost 2 seats. *

– Lost 8 seats *

– No extra or fewer seats allocated. *

– Gained 10 seats

References

Bibliography

Boundary Commission for N.I. Fifth Periodical Report (HM Command Paper 73) – Parliamentary Constituencies of Northern Ireland. Retrieved 2013-07-19
{{Use dmy dates, date=April 2017 Politics of the United Kingdom 2010 United Kingdom general election 2015 United Kingdom general election 2017 United Kingdom general election