The Parliament of the United Kingdom currently has 650 parliamentary constituencies across the constituent countries ( England, Scotland, Wales and Northern Ireland), each electing a single member of parliament (MP) to the House of Commons by the

plurality Plurality may refer to: Voting * Plurality (voting), or relative majority, when a given candidate receives more votes than any other but still fewer than half of the total ** Plurality voting, system in which each voter votes for one candidate and ...

( first past the post) voting system, ordinarily every five years. Voting last took place in all 650 of those constituencies at the United Kingdom general election on 12 December 2019. 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 In many countries, a statutory instrument is a form of delegated legislation. United Kingdom Statutory instruments are the principal form of delegated or secondary legislation in the United Kingdom. National government Statutory instrument ...

. Constituencies in Scotland remained unchanged, as the Boundary Commission for Scotland 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 legislature, legislative and executive (government), executive branches of ...

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 1986. 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 ele ...

, as amended by the Parliamentary Constituencies Act 2020, 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 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 European Union an ...

Overview

The table below gives the number of eligible voters broken down by constituent country, including the average constituency size in each country.

Geographical size of constituencies

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

Parliamentary constituencies in the United Kingdom

Size of electorate in each United Kingdom house of commons constituency

The "Region" of the table refers to the NUTS 1 statistical region of England, which coincides with the former European Parliament constituency in which the constituency was included until 31 January 2020. As of the 2019 election there are 533 constituencies in England, 40 in Wales, 59 in Scotland and 18 in Northern Ireland.

England

Scotland

Wales

Northern Ireland

Summary of main boundary changes for the 2010 general election

* Scotland – No changes from 2005 election. * Wales – Number of seats unchanged: three seats were abolished and three were created: Aberconwy, Arfon, and Dwyfor Meirionnydd. * Northern Ireland – No extra or fewer seats allocated. * England: :*The

non-metropolitan counties A non-metropolitan county, or colloquially, shire county, is a metropolitan and non-metropolitan counties of England, county-level entity in England that is not a metropolitan county. The counties typically have populations of 300,000 to 1.8 mil ...

of Cornwall, Derbyshire, Devon, Essex, Hampshire, Lancashire, Norfolk, Northamptonshire, Warwickshire and Wiltshire each gained one seat. :*Following the abolition of the county of Avon, each of the four successor authorities ( Bristol, South Gloucestershire, Bath and North East Somerset, and North Somerset) were considered separately, resulting in significant changes, gaining one seat overall. :*The

metropolitan counties The metropolitan counties are a type of county-level administrative division of England. There are six metropolitan counties, which each cover large urban areas, with populations between 1 and 3 million. They were created in 1974 and are each di ...

of Greater Manchester, Merseyside, Tyne and Wear, South Yorkshire,

West Midlands West or Occident is one of the four cardinal directions or points of the compass. It is the opposite direction from east and is the direction in which the Sun sets on the Earth. Etymology The word "west" is a Germanic word passed into some ...

and West Yorkshire each lost a seat. :* Inner London gained one seat while northern and eastern parts of Outer London each lost one. :*The City of York was reviewed separately and was divided into two seats, neither overlapping part of North Yorkshire. :* Herefordshire and Worcestershire, to reflect their full reinstatement as separate counties, were considered in separate reviews, leading to Herefordshire being split into two constituencies, each entirely within the county. :* Isle of Wight maintained its status as one constituency, the largest by

electorate Electorate may refer to: * The people who are eligible to vote in an election, especially their number e.g. the term ''size of (the) electorate'' * The dominion of a Prince-elector in the Holy Roman Empire until 1806 * An electoral district An ...

Current boundary reviews

Following the abandonment of the Sixth Periodic Review (the 2018 review), the Boundary Commission for England formally launched the 2023 Review on 5 January 2021. It is due to be completed by July 2023. ''See

2023 Periodic Review of Westminster constituencies The 2023 Periodic Review of Westminster constituencies is the current cycle of the process to redraw the constituency map for the House of Commons. The process for periodic reviews of parliamentary constituencies in the United Kingdom is gover ...

for further details.''

References

Bibliography

Boundary Commission for N.I. Fifth Periodical Report (HM Command Paper 73) – Parliamentary Constituencies of Northern Ireland. Retrieved 2013-07-19
{{DEFAULTSORT:List Of United Kingdom Parliament Constituencies Politics of the United Kingdom 2010 United Kingdom general election 2015 United Kingdom general election 2017 United Kingdom general election