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 separate boundary commissions:
Each commission comprises four members, three of whom take part in meetings. The Speaker of the House of Commons is ex officio chairman of each of the boundary commissions. However, the Speaker does not play any part in proceedings, and a Justice is appointed to each boundary commission as Deputy Chairman Commissioner.
The boundary commissions, which are required to report every eight years, must apply a set series of rules when devising constituencies. These rules are set out in the Parliamentary Constituencies Act 1986, as amended by the Parliamentary Voting System and Constituencies Act 2011 and subsequently by the Parliamentary Constituencies Act 2020.
Firstly, each proposed constituency has to comply with two numerical limits:
There are a small number of exceptions to the numerical limit on electorate which are specified in the legislation:
Having satisfied the electorate and area requirements, each commission can also take into account a number of other factors:
As these factors can to an extent be mutually conflicting, each commission has discretion on how it applies them. In so doing, each commission aims for a consistent approach within a review.
When a commission publishes its proposals for public consultation, the consultation periods are specified in the legislation:
It has been normal practice for local government electoral wards to be used as building blocks for constituencies, although there is no legislative requirement to do so. In some metropolitan boroughs in England, and in Scotland, following the introduction of multi-member wards in 2007, it is often difficult to do so due to the large electorates in these wards, and therefore a collection of complete wards may not give an electorate that is within the required electoral range.
The law specifies that the electorate used during a review is the registered electorate at the time of the start of the review, and not the electorate at the end of a review, or the total population.
Boundary changes can have a significant effect on the results of elections,but boundary commissions do not take any account of voting patterns in their deliberations, or consider what the effect of their recommendations on the outcome of an election may be.
Once a commission has completed its review, it submits a report to the appropriate Secretary of State who lays it before Parliament. Once all four reports have been submitted, an Order in Council which gives effect to the recommendations must be submitted within four months to the Privy Council. The Government may not modify any of the commissions' recommendations unless specifically requested to do so by the relevant commission. On approval by the Privy Council, the new constituencies come into effect for the next general election. Any by-elections before then use the pre-existing boundaries.
These provisions were brought in by the Parliamentary Constituencies Act 2020. Previously, Parliament voted on the recommendations and, although it could not make any alterations to them, it could reject them in their entirety. In addition, although this power was never exercised, for many years the legislation gave the Secretary of State the power to modify a commission's recommendations. The new procedures further strengthen the separation of the creation of constituency boundaries from those elected for the resulting electoral areas, with the aim of eliminating any scope for gerrymandering.
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.
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 previous rules, 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 earlier legislation, the terms of review were significantly different:
The most recentgeneral review, known as the Fifth Periodic Review 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 most recent general review in Scotland was given effect in 2005, and the resulting constituencies were used in the May 2005 general election.
There are currently 533 constituencies in England, 40 constituencies in Wales, 59 constituencies in Scotland and 18 constituencies in Northern Ireland, providing a total of 650.
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 coalition government consensus 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.
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.They are due to issue their final reports by 1 July 2023. Under the rules governing the number of constituencies in each nation, England will have 543 constituencies (+10), Wales 32 (-8), Scotland 57 (-2) and Northern Ireland 18 (unchanged).
The scope of the boundary commissions' work is limited to areas for election to the UK House of Commons.
Local authority areas and electoral areas are reviewed by the separate but similarly-named:
Changes to parliamentary boundaries do not themselves impact on which local councils are responsible for any area.
The procedure for reviews of constituencies and regions for the Scottish Parliament is set down by the Scotland Act 1998. That Act specifies that there are 73 constituencies for the Scottish Parliament: the Orkney Islands, the Shetland Islands and 71 others. The Act also specifies that the constituencies are grouped into eight regions to allow the return of list members elected by proportional representation to the parliament. The Boundary Commission for Scotland conducted a review of these boundaries between 2007 and 2010,and their recommendations were implemented from 2011. Since the legislation requires different numbers of constituencies in Scotland for the United Kingdom Parliament and the Scottish Parliament, these two sets of areas do not fit together neatly. Responsibility for Scottish Parliament boundary reviews passed to the Local Government Boundary Commission for Scotland in May 2017.
The Government of Wales Act 2006 specified that the constituencies for the then National Assembly for Wales were to be the same as those for the UK Parliament at Westminster. The Act required the Boundary Commission for Wales to group the constituencies into electoral regions, to allow the return of list members elected by proportional representation to the Assembly. The Boundary Commission for Wales's Fifth General Review resulted in revised Assembly constituencies and electoral regions. The Parliamentary Voting System and Constituencies Act 2011 removed the link with Westminster constituencies, and there is currently no statutory review body for Senedd constituencies.
The Boundary Commission reported in 2016 proposing to reduce the number of UK Parliament constituencies in Wales to 29, on the basis that all constituencies must have at least 71,031 voters.While the Parliamentary Voting System and Constituencies Act 2011 removed the link between UK Parliament and Senedd seat boundaries, organisations such as the Electoral Reform Society have indicated a preference for coterminosity (meaning the mirroring of seat boundaries in Wales along the lines of the 2016 proposed reforms to the Welsh seats in the UK Parliament).
Section 33 of the Northern Ireland Act 1998 provides that the constituencies for the Northern Ireland Assembly are the same as the constituencies that are used for the United Kingdom Parliament. From 1998-2016 six members were elected from each constituency;the Assembly Members (Reduction of Numbers) Act (Northern Ireland) 2016 reduced this to five members.
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.
In the United Kingdom (UK), each of the electoral areas or divisions called constituencies elects one member to the House of Commons.
The Parliament of the United Kingdom currently has 650 parliamentary constituencies across the constituent countries, each electing a single member of parliament (MP) to the House of Commons by the plurality voting system, ordinarily every five years. Voting last took place in all 650 of those constituencies at the United Kingdom general election on 12 December 2019.
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.
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.
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 House of Commons Act 1944 was an Act of the Parliament of the United Kingdom that established permanent boundary commissions for each of the constituent countries of the United Kingdom, and 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.
The Sixth Periodic Review of Westminster constituencies, also known as the 2013 Review, 2018 Review, or just boundary changes, was an ultimately unfruitful cycle of the process by which constituencies of the House of Commons of the United Kingdom are reviewed and redistributed. The four UK boundary commissions carried out their reviews between 2011 and 2018, but their recommendations were not taken up by the government and were formally laid aside in 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 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 is the successor to the Sixth Periodic Review of Westminster constituencies, which was ultimately abandoned after two successive proposals by the Commissions failed to pass into law.