United Kingdom Parliament constituencies

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 (first past the post) system of election, ordinarily every five years. Voting last took place in all 650 of those constituencies at the United Kingdom general election on 12 December 2019, and these results have been counted and verified.

The number of seats rose from 646 to 650 at the 2005 general election after proposals made by the boundary commissions for England, Wales and Northern Ireland were adopted through statutory instruments. Constituencies in Scotland remained unchanged, as the Boundary Commission for Scotland had completed a review just before the 2005 general election.

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. For the 2013 review this was primarily the Parliamentary Voting System and Constituencies Act 2011. 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 EU Parliament Elections).

The electorate figures given in the second column of the tables below are those as of 2017.

Parliamentary constituencies in the United Kingdom

The "region" of the table refers to the former European Parliament constituency that the constituency was situated in until 31 January 2020.

England

Scotland

Wales

Northern Ireland

Electorate summary

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:
North Yorkshire, Hampshire, Warwickshire, Derbyshire, Norfolk, Essex, Lancashire, Northamptonshire and Cornwall gained seats. Isle of Wight maintained its status as one constituency, the largest by electorate.
The City of York was divided into two seats, neither overlapping part of North Yorkshire.
North London, Birmingham and the metropolitan counties of Greater Manchester, Merseyside, Tyne and Wear and South Yorkshire lost a seat each.
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.
Bath, Bristol and Somerset underwent arguably the most significant changes to reflect the abolition of Avon.

Updated electorate figures from December 2010 have been added for the English, Northern Irish, Scottish and Welsh constituencies.

Geographical area of constituencies
The constituency with the greatest geographical area in the UK is Ross, Skye and Lochaber, at about . The largest in Wales is Brecon and Radnorshire. The smallest constituency by area is Islington North at .

See also
Member of Parliament
Lists of electoral districts by nation

References

Bibliography
Boundary Commission for N.I. Fifth Periodical Report (HM Command Paper 73) – Parliamentary Constituencies of Northern Ireland. Retrieved 2013-07-19.

 
Category:Politics of the United Kingdom
Category:2010 United Kingdom general election
Category:2015 United Kingdom general election
Category:2017 United Kingdom general election