The Parliament of the United Kingdom currently has 650 parliamentary

constituencies An electoral district, also known as an election district, legislative district, voting district, constituency, riding, ward, division, or (election) precinct is a subdivision of a larger state (a country, administrative region, or other poli ...

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 ( first past the post) voting system, ordinarily every five years.

Voting Voting is a method by which a group, such as a meeting or an electorate, can engage for the purpose of making a collective decision or expressing an opinion usually following discussions, debates or election campaigns. Democracies elect holde ...

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 The Fifth Periodic Review of Westminster constituencies was undertaken between 2000 and 2007 by the four boundary commissions for England, Scotland, Wales and Northern Ireland for the UK Parliament. The changes for England, Wales and Northern ...

) were adopted through statutory instruments. Constituencies in Scotland remained unchanged, as the

Boundary Commission for Scotland The boundary commissions in the United Kingdom are non-departmental public bodies responsible for determining the boundaries of constituencies for elections to the House of Commons. There are four boundary commissions: * Boundary Commission for E ...

had completed a review just before the 2005 general election, which had resulted in a reduction of 13 seats. Primary legislation 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, as amended by the

Parliamentary Constituencies Act 2020 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 ...

, 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).

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 county-level entity in England that is not a metropolitan county. The counties typically have populations of 300,000 to 1.8 million. The term ''shire county'' is, however, an unoff ...

of Cornwall, Derbyshire, Devon,

Essex Essex () is a county in the East of England. One of the home counties, it borders Suffolk and Cambridgeshire to the north, the North Sea to the east, Hertfordshire to the west, Kent across the estuary of the River Thames to the south, and Gr ...

, 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 Bristol () is a city, ceremonial county and unitary authority in England. Situated on the River Avon, it is bordered by the ceremonial counties of Gloucestershire to the north and Somerset to the south. Bristol is the most populous city in ...

, South Gloucestershire,

Bath and North East Somerset Bath and North East Somerset (B&NES) is a unitary authority district in England. Bath and North East Somerset Council was created on 1 April 1996 following the abolition of the county of Avon. It is part of the ceremonial county of Somerset. Th ...

, and North Somerset) were considered separately, resulting in significant changes, gaining one seat overall. :*The metropolitan counties of Greater Manchester,

Merseyside Merseyside ( ) is a metropolitan and ceremonial county in North West England, with a population of 1.38 million. It encompasses both banks of the Mersey Estuary and comprises five metropolitan boroughs: Knowsley, St Helens, Sefton, Wirra ...

, Tyne and Wear,

South Yorkshire South Yorkshire is a ceremonial and metropolitan county in the Yorkshire and Humber Region of England. The county has four council areas which are the cities of Doncaster and Sheffield as well as the boroughs of Barnsley and Rotherham. In N ...

, West Midlands and West Yorkshire each lost a seat. :*

Inner London Inner London is the name for the group of London boroughs which form the interior part of Greater London and are surrounded by Outer London. With its origins in the bills of mortality, it became fixed as an area for statistics in 1847 and was use ...

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 Herefordshire () is a county in the West Midlands of England, governed by Herefordshire Council. It is bordered by Shropshire to the north, Worcestershire to the east, Gloucestershire to the south-east, and the Welsh counties of Monmouthsh ...

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 or c ...

Current boundary reviews

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

Boundary Commission for England The boundary commissions in the United Kingdom are non-departmental public bodies responsible for determining the boundaries of constituencies for elections to the House of Commons. There are four boundary commissions: * Boundary Commission for E ...

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