The

Parliament of the United Kingdom The Parliament of the United Kingdom is the supreme legislative body of the United Kingdom, the Crown Dependencies and the British Overseas Territories. It meets at the Palace of Westminster, London. It alone possesses legislative suprema ...

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 polity ...

across the constituent countries (

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...

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

and

Northern Ireland Northern Ireland ( ga, Tuaisceart Éireann ; sco, label= Ulster-Scots, Norlin Airlann) is a part of the United Kingdom, situated in the north-east of the island of Ireland, that is variously described as a country, province or region. Nort ...

), each electing a single

member of parliament A member of parliament (MP) is the representative in parliament of the people who live in their electoral district. In many countries with bicameral parliaments, this term refers only to members of the lower house since upper house members of ...

(MP) to the

House of Commons The House of Commons is the name for the elected lower house of the 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 parliament. ...

by the plurality (

first past the post In a first-past-the-post electoral system (FPTP or FPP), formally called single-member plurality voting (SMP) when used in single-member districts or informally choose-one voting in contrast to ranked voting, or score voting, voters cast their ...

) 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 Ir ...

) 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 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 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 The Parliamentary Constituencies Act 1986 (c. 56) is an Act of the Parliament of the United Kingdom. It is the legislation defining the constitution and work of the four parliamentary Boundary Commissions in the UK. A copy of the current text o ...

. 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 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 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 Members of the European Parliament (MEPs) are elected by the population of the member states of the European Union (EU). The European Electoral Act 2002 allows member states the choice to allocate electoral subdivisions or constituencies (, ...

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

– No changes from 2005 election. *

– Number of seats unchanged: three seats were abolished and three were created: Aberconwy, Arfon, and Dwyfor Meirionnydd. *

– No extra or fewer seats allocated. *

: :*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 unoffi ...

Cornwall Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic ...

Derbyshire Derbyshire ( ) is a ceremonial county in the East Midlands, England. It includes much of the Peak District National Park, the southern end of the Pennine range of hills and part of the National Forest. It borders Greater Manchester to the nor ...

Devon Devon ( , historically known as Devonshire , ) is a ceremonial and non-metropolitan county in South West England. The most populous settlement in Devon is the city of Plymouth, followed by Devon's county town, the city of Exeter. Devon is ...

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 G ...

Hampshire Hampshire (, ; abbreviated to Hants) is a ceremonial county, ceremonial and non-metropolitan county, non-metropolitan counties of England, county in western South East England on the coast of the English Channel. Home to two major English citi ...

Lancashire Lancashire ( , ; abbreviated Lancs) is the name of a historic county, ceremonial county, and non-metropolitan county in North West England. The boundaries of these three areas differ significantly. The non-metropolitan county of Lancashi ...

Norfolk Norfolk () is a ceremonial and non-metropolitan county in East Anglia in England. It borders Lincolnshire to the north-west, Cambridgeshire to the west and south-west, and Suffolk to the south. Its northern and eastern boundaries are the No ...

Northamptonshire Northamptonshire (; abbreviated Northants.) is a county in the East Midlands of England. In 2015, it had a population of 723,000. The county is administered by two unitary authorities: North Northamptonshire and West Northamptonshire. It is ...

Warwickshire Warwickshire (; abbreviated Warks) is a county in the West Midlands region of England. The county town is Warwick, and the largest town is Nuneaton. The county is famous for being the birthplace of William Shakespeare at Stratford-upon-Avon an ...

and

Wiltshire Wiltshire (; abbreviated Wilts) is a historic and ceremonial county in South West England with an area of . It is landlocked and borders the counties of Dorset to the southwest, Somerset to the west, Hampshire to the southeast, Gloucestershire ...

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 South Gloucestershire is a unitary authority area in the ceremonial county of Gloucestershire, South West England. Towns in the area include Yate, Chipping Sodbury, Thornbury, Filton, Patchway and Bradley Stoke, the latter three forming part ...

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 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 ...

Greater Manchester Greater Manchester is a metropolitan county and combined authority, combined authority area in North West England, with a population of 2.8 million; comprising ten metropolitan boroughs: City of Manchester, Manchester, City of Salford, Salford ...

Merseyside Merseyside ( ) is a metropolitan county, metropolitan and ceremonial counties of England, ceremonial county in North West England, with a population of List of ceremonial counties of England, 1.38 million. It encompasses both banks of the Merse ...

Tyne and Wear Tyne and Wear () is a metropolitan county in North East England, situated around the mouths of the rivers Tyne and Wear. It was created in 1974, by the Local Government Act 1972, along with five metropolitan boroughs of Gateshead, Newcastl ...

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 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 West Yorkshire is a metropolitan and ceremonial county in the Yorkshire and Humber Region of England. It is an inland and upland county having eastward-draining valleys while taking in the moors of the Pennines. West Yorkshire came into exi ...

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 Outer London is the name for the group of London boroughs that form a ring around Inner London. Together, the inner and outer boroughs form London, the capital city of the United Kingdom. These were areas that were not part of the County of Londo ...

each lost one. :*The City of

York York is a cathedral city with Roman origins, sited at the confluence of the rivers Ouse and Foss in North Yorkshire, England. It is the historic county town of Yorkshire. The city has many historic buildings and other structures, such as a ...

was reviewed separately and was divided into two seats, neither overlapping part of

North Yorkshire North Yorkshire is the largest ceremonial counties of England, ceremonial county (lieutenancy area) in England, covering an area of . Around 40% of the county is covered by National parks of the United Kingdom, national parks, including most of ...

. :*

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 Monmouthshire ...

and

Worcestershire Worcestershire ( , ; written abbreviation: Worcs) is a county in the West Midlands of England. The area that is now Worcestershire was absorbed into the unified Kingdom of England in 927, at which time it was constituted as a county (see His ...

, 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 The Isle of Wight ( ) is a county in the English Channel, off the coast of Hampshire, from which it is separated by the Solent. It is the largest and second-most populous island of England. Referred to as 'The Island' by residents, the Isle of ...

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 The prince-electors (german: Kurfürst pl. , cz, Kurfiřt, ...

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 ...

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