Legislation The commissions are currently established under the
Parliamentary Constituencies Act 1986, most recently amended by the
Parliamentary Voting System and Constituencies Act 2011. They were first established as permanent bodies under the
House of Commons (Redistribution of Seats) Act 1944. The 1944 Act was amended in 1947 and then replaced by the
House of Commons (Redistribution of Seats) Act 1949. The 1949 Act was amended in 1958 and 1979 and replaced by the
Parliamentary Constituencies Act 1986; changes in
legislation from 1944 to 1986 were generally incremental in nature. The
Political Parties, Elections and Referendums Act 2000 under
PM Tony Blair's government envisaged that the functions of the boundary commissioners would be transferred to the
United Kingdom Electoral Commission, but this never transpired: the
Local Democracy, Economic Development and Construction Act 2009 repealed the
Act of Parliament (of 2000) effective from 1 April 2010. The
Parliamentary Voting System and Constituencies Act 2011 passed under the
Con-Lib Dem coalition government made substantial changes to the legislation governing constituency boundary reviews; this was further amended by the
Parliamentary Constituencies Act 2020.
Past reviews of UK Parliament constituencies Customarily, each commission conducted a complete review of all constituencies in its part of the United Kingdom every eight to twelve years. In between these general reviews, the commissions were able to conduct interim reviews of part of their area of responsibility. The interim reviews usually did not yield drastic changes in boundaries, while the general reviews generally did. Under the rules in force before 2011, the number of constituencies in Great Britain (England, Wales, and Scotland) had to "not be substantially greater or less than 613", of which at least 35 had to be in Wales. The
City of London was not to be partitioned and was to be included in a seat that referred to it by name. The
Orkney and
Shetland Islands were not to be combined with any other areas. Northern Ireland had to have between 16 and 18 constituencies. Under the
Parliamentary Constituencies Act 1986, the terms of review were significantly different: • the total number of constituencies was not fixed (
see above): each commission had limited discretion to specify the number in its part of the United Kingdom; • the size of the electorates was just one of several rules, rather than being subject to a numerical limit which overrides other factors; • there was not previously a limit on the area of a constituency, but in practice, no constituency has ever exceeded the 13,000 square kilometre limit introduced by the 2011 Act; • the consultation mechanism was significantly different: consultation periods only lasted four weeks, and could be followed by local inquiries; • reviews were only carried out every eight to twelve years instead of every five years. The constituency boundaries used for the elections between 2010 and 2019 were mostly established by the
Fifth Periodic Review, which was given effect in Wales by an Order made in 2006, in England by an Order from 2007 and in Northern Ireland by an Order from 2008, with the new boundaries used for the
May 2010 general election. The Scottish boundaries used in those elections were given effect in 2005, and were already used in the
May 2005 general election. Under the Fifth Periodic Review, there were 533 constituencies in England, 40 constituencies in Wales, 59 constituencies in Scotland and 18 constituencies in Northern Ireland, providing a total of 650.
Sixth Periodic Review The
Sixth Periodic Review of Westminster constituencies was launched on 4 March 2011 by the Boundary Commission for England, the Boundary Commission for Scotland, the Boundary Commission for Wales and the Boundary Commission for Northern Ireland. The Sixth Review would have resulted in 600 constituencies for the
United Kingdom Parliament: a reduction from the 650 constituencies in existence at the
2010 general election. In January 2013, parliamentary opposition to proposed legislative amendments because of a lack of consensus in the coalition resulted in the review being suspended. Following the
Conservative victory at the
2015 general election, the review was recommenced in 2016 and final recommendations were submitted by the four commissions in September 2018 and laid before Parliament. However the revised proposals were never brought forward by the Government for approval and, further to the passing of the
Parliamentary Constituencies Act 2020, the Sixth Review was formally abandoned.
2023 review , labelled. Following the passing of the 2020 Act, which reinstated the number of constituencies to 650, a new review, known as the
2023 Review, was launched by the four commissions on 5 January 2021. Under the new rules governing the number of constituencies in each nation, England would have 543 constituencies (+10), Wales 32 (-8), Scotland 57 (-2) and Northern Ireland 18 (unchanged). The final consultation for England began on 8 November 2022 with the publication of the Revised Proposals and lasted for four weeks, ending on 5 December. All four Commissions submitted their Final Recommendations Reports to the Speaker of the House of Commons on 27 June 2023. An
order in council adopting the recommendations,
The Parliamentary Constituencies Order 2023 (No. 1230 of 2023), was made on 15 November 2023 and came into force on 29 November 2023. ==Relationship with local government, devolved parliaments and assemblies==