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:
Over the history of the House of Commons, the number of Members of Parliament (MPs) has varied for assorted reasons, with increases in recent years due to increases in the population of the United Kingdom. There are currently 650 constituencies, each sending one MP to the House of Commons, corresponding to approximately one for every 92,000 people, or one for every 68,000 parliamentary electors.
Islington North is a constituency in Greater London represented in the House of Commons of the UK Parliament since 1983 by Jeremy Corbyn, who was Leader of the Labour Party and Leader of the Opposition from 2015 to 2020.
In the United Kingdom (UK), each of the electoral areas or divisions called constituencies elects one member to the House of Commons.
The Representation of the People Act 1948 was an Act of the Parliament of the United Kingdom that altered the law relating to parliamentary and local elections. It is noteworthy for abolishing plural voting for parliamentary elections, including by the abolition of the twelve separate university constituencies; and for again increasing the number of members overall, in this case to 613.
"Unreformed House of Commons" is a name given to the House of Commons of Great Britain before it was reformed by the Reform Act 1832, the Irish Reform Act 1832, and the Scottish Reform Act 1832.
The Redistribution of Seats Act 1885 was an Act of the Parliament of the United Kingdom. It was a piece of electoral reform legislation that redistributed the seats in the House of Commons, introducing the concept of equally populated constituencies, a concept in the broader global context termed equal apportionment, in an attempt to equalise representation across the UK. It was associated with, but not part of, the Representation of the People Act 1884.
Duncairn, a division of the parliamentary borough of Belfast, was a UK parliamentary constituency in Ireland. It returned one Member of Parliament (MP) to the House of Commons of the United Kingdom from 1918 to 1922, using the first past the post electoral system.
Tain Burghs, was a constituency of the House of Commons of the Parliament of Great Britain from 1708 to 1801 and of the Parliament of the United Kingdom from 1801 to 1832, sometimes known as Northern Burghs. It was represented by one Member of Parliament (MP).
Scottish Westminster constituencies were Scottish constituencies of the House of Commons of the Parliament of Great Britain, normally at the Palace of Westminster, from 1708 to 1801, and have been constituencies of the House of Commons of the Parliament of the United Kingdom, also at Westminster, since 1801. Constituency boundaries have changed on various occasions, and are now subject to both periodical and ad hoc reviews of the Boundary Commission for Scotland.
Multi-member constituencies existed in the Parliament of the United Kingdom and its predecessor bodies in the component parts of the United Kingdom from the earliest era of elected representation until they were abolished by the Representation of the People Act 1948. Since the 1950 general election, all members of the House of Commons have been elected from single-member 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 Ireland took effect at the 2010 United Kingdom general election; that for Scotland took effect at the 2005 election. All of the recommendations were approved.
Birmingham Moseley was a constituency of the House of Commons of the Parliament of the United Kingdom from 1918 to 1950. It elected one Member of Parliament (MP) by the first-past-the-post system of election.
The House of Commons Act 1949 was an Act of the Parliament of the United Kingdom that provided for the periodic review of the number and boundaries of parliamentary constituencies.
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 elections to the UK Parliament and also made provision on the number and size of parliamentary constituencies. The Bill for the Act was introduced to the House of Commons on 22 July 2010 and passed third reading on 2 November by 321 votes to 264. The House of Lords passed the Bill, with amendments, on 14 February 2011, and after some compromises between the two Houses on amendments, it received Royal Assent on 16 February 2011.
The 2023 Periodic Review of Westminster constituencies was the most recent 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 governed by the Parliamentary Constituencies Act 1986, as amended by the Parliamentary Voting System and Constituencies Act 2011 and subsequently by the Parliamentary Constituencies Act 2020. This review was the successor to the 2018 Periodic Review of Westminster constituencies, which was ultimately abandoned after it failed to pass into law.
The ceremonial county of Cheshire, which comprises the unitary authorities of Cheshire East, Cheshire West and Chester, Halton and Warrington, has returned 11 MPs to the UK Parliament since 1997.
The county of Northumberland has returned four MPs to the UK Parliament since 1983. Under the Local Government Act 1972, which came into effect on 1 April 1974, the boundaries of the historic/administrative county were significantly altered with the south-east of the county, comprising more than half the electorate, being transferred to the new metropolitan county of Tyne and Wear. These changes were reflected in the following redistribution of parliamentary seats which did not come into effect until the 1983 general election, resulting in a reduction in the county's representation from 10 to 4 MPs.
