In the United Kingdom (UK), each of the electoral areas or divisions called constituencies elects one or more members to a parliament or assembly.
- The House of Commons (see United Kingdom Parliament constituencies)
- The Scottish Parliament (see Scottish Parliament constituencies and regions)
- The Northern Ireland Assembly (see Northern Ireland Assembly constituencies)
- The National Assembly for Wales (see National Assembly for Wales constituencies and electoral regions)
- The London Assembly (see London Assembly constituencies)
Between 1921 and 1973 the following body also included members elected by constituencies:
County constituencies and borough constituencies 
House of Commons, Northern Ireland Assembly, Scottish Parliament and Welsh Assembly constituencies are designated as either county or borough constituencies, except that in Scotland the term burgh is used instead of borough. Borough constituencies are predominantly urban while county constituencies are predominantly rural. There is no definitive statutory criterion for the distinction; the Boundary Commission for England has stated that, "as a general principle, where constituencies contain more than a small rural element they should normally be designated as county constituencies. Otherwise they should be designated as borough constituencies."
Since the advent of universal suffrage, the differences between county and borough constituencies are slight. The returning officer in a county constituency is the high sheriff of the county; in a borough constituency it is the mayor or district council head. The spending limits for election campaigns are different in the two, the reasoning being that candidates in county constituencies tend to need to travel further.
|Elected body||Constituency type|
|House of Commons||£7,150 + 5p per elector||£7,150 + 7p per elector|
|Northern Ireland Assembly||£5,483 + 4.6p per elector||£5,483 + 6.2p per elector|
|£5,761 + 4.8p per elector||£5,761 + 6.5p per elector|
In the House of Commons of England, each English county elected two "knights of the shire" while each enfranchised borough elected "burgesses" (usually two, sometimes four, and in a few cases one). From 1535 each Welsh county and borough was represented, by one one knight or burgess. Until 1950 there were also university constituencies, which gave graduates an additional representation. The franchise was restricted differently in different types of constituency; in county constituencies forty shilling freeholders (i.e. landowners) could vote, while in boroughs the franchise varied from potwallopers, giving many residents votes, to rotten boroughs with hardly any voters.
Similar distinctions applied in the Irish House of Commons, while the non-university elected members of the Parliament of Scotland were called Shire Commissioners and Burgh Commissioners. After the Acts of Union 1707, Scottish burghs were grouped into districts of burghs in the Parliament of Great Britain, except that Edinburgh was a constituency in its own right. After the Acts of Union 1800, smaller Irish boroughs were disenfranchised, while most others returned only one MP to the United Kingdom Parliament.
The Reform Act 1832 reduced the number of parliamentary boroughs by eliminating the rotten boroughs. It also divided larger counties into two two-seat divisions, the boundaries of which were defined in the Parliamentary Boundaries Act 1832, and gave seven counties a third member. The Redistribution of Seats Act 1885 equalised the population of constituencies; it split larger boroughs into multiple single-member constituencies, reduced smaller boroughs from two seats each to one, split each two-seat county and division into two single-member constituencies, and each three-seat county into single-member constituencies.
The Parliamentary Voting System and Constituencies Act 2011 gives the Boundary Commissions for England, Wales, Scotland and Northern Ireland the power to create names for constituencies, and does not provide a set of statutory guidelines for the Commissions to follow in doing so.
Constituency names are geographic, and "should normally reflect the main population centre(s) contained in the constituency". Compass points are used to distinguish constituencies from each other when a more suitable label cannot be found. Where used, "The compass point reference used will generally form a prefix in cases where the rest of the constituency name refers to the county area or a local council, but a suffix where the rest of the name refers to a population centre." This is the reason for the difference in naming between, for example, South Shropshire (a county constituency) and Reading West (a borough constituency. 
House of Commons constituencies 
In the 2005 United Kingdom general election, the House of Commons had 646 constituencies covering the whole of the United Kingdom. This rose to 650 in the 2010 election. Each constituency elects one Member of Parliament (MP) by the "first past the post" system of election.
See also 
- List of United Kingdom Parliament constituencies
- Former United Kingdom Parliament constituencies
- Constituencies in the next United Kingdom general election
- University constituency
- Number of Westminster MPs
London Assembly constituencies 
There are fourteen London Assembly constituencies covering the Greater London area, and each constituency elects one member of the assembly by the first past the post system of election. Also, eleven additional members are elected from Greater London as a whole to produce a form or degree of mixed member proportional representation.
Constituency names and boundaries remain now as they were for the first general election of the assembly, in 2000.
Northern Ireland Assembly constituencies 
|This section requires expansion. (June 2008)|
Each elects 6 MLAs to the 108 member NI Assembly by means of the Single Transferrable Vote system. Assembly Constituency boundaries are usually linked to their House of Commons equivalents (which also are 18 in number, although they only elect 1 MP to serve).
The constituencies below are not used for the election of members to the 26 district councils.
Scottish Parliament constituencies 
Scottish Parliament constituencies are sometimes called Holyrood constituencies, to distinguish them from Westminster (House of Commons) constituencies. The Scottish Parliament Building is in the Holyrood area of Edinburgh, while the main meeting place of the Parliament of the United Kingdom is the Palace of Westminster, in the City of Westminster.
There are 73 Holyrood constituencies covering Scotland, and each elects one Member of the Scottish Parliament (MSP) by the first past the post system of election. Also, the constituencies are grouped into eight electoral regions, and each of these regions elects seven additional members, to produce a form or degree of mixed member proportional representation.
The existing constituencies were created, effectively, for the first general election of the Scottish Parliament, in 1999. When created, all but two had the names and boundaries of Westminster constituencies. The two exceptions were the Orkney Holyrood constituency, covering the Orkney Islands council area, and the Shetland Holyrood constituency, covering the Shetland Islands council area. For Westminster elections, these council areas were covered (and still are covered) by the Orkney and Shetland Westminster constituency.
In 1999, under the Scotland Act 1998, the expectation was that there would be a permanent link between the boundaries of Holyrood constituencies and those of Westminster constituencies. This link was broken, however, by the Scottish Parliament (Constituencies) Act 2004, which enabled the creation of a new set of Westminster constituencies without change to Holyrood constituencies. The new Westminster boundaries became effective for the United Kingdom general election, 2005.
Welsh Assembly constituencies 
There are 40 Welsh Assembly constituencies covering Wales, and each elects one Assembly Member (AM) by the first past the post system of election. Also, the constituencies are grouped into five electoral regions, and each of these regions elects four additional members, to produce a form or degree of mixed member proportional representation.
The current set of Assembly constituencies is the second to be created. The first was created for the first general election of the Assembly, in 1999.
European Parliament constituencies 
There are twelve European Parliament constituencies covering the United Kingdom. All except one are entirely within the UK. The exception is the South West England constituency, which includes Gibraltar. Each constituency elects a number of Members of the European Parliament (MEPs) the d'Hondt method of party-list proportional representation.
The current set of UK European Parliament constituencies was first used in the 1999 European Parliament election.
Notes and references 
- Boundary Commission for England (2007), Fifth periodical report, Norwich: TSO (The Stationery Office), ISBN 0-10-170322-8
- "Representation of the People Act 1983", Acts of the United Kingdom Parliament 1983 (2), 1983-02-08: 76(2)(a), retrieved 2008-11-04
- Statutory Instrument 2005 No. 269 (section 3) The Representation of the People (Variation of Limits of Candidates' Election Expenses) Order 2005 (Coming into force 2005-03-04)
- "Representation of the People Act 1983", Acts of the United Kingdom Parliament 1983 (2), 1983-02-08: 76(2)(aa), retrieved 2008-11-04
- "Political Parties, Elections and Referendums Act 2000", Acts of the United Kingdom Parliament 2000 (41), 2000-11-30: 132(5), retrieved 2008-11-04
- http://consultation.boundarycommissionforengland.independent.gov.uk/wp-content/uploads/2011/08/406678_Guide-to-the-2013-Review_acc.pdf page 10, Boundary Commission for England, "A guide to the 2013 Review" Sections 41-44, 'Naming'
- Scotland Act 1998, Office of Public Sector Information website
- Scottish Parliament (Constituencies) Act 2004, Office of Public Sector Information website
- Gibraltar should join South West for elections to European Parliament, Electoral Commission new release, 28 Aug 2003
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