Westminster Parliamentary Constituencies
Due to the way in which boundaries are defined, constituency boundaries do not necessarily correspond exactly with those of European electoral regions. Parliamentary constituencies are used to elect MPs (Members of Parliament) to the House of Commons, the UK's primary legislative chamber at Westminster. At the June 2001 general election there were 659 constituencies, each electing one MP using the first-past-the-post system.
Constituencies are formed from groups of adjoining electoral wards/divisions and very often follow higher authority boundaries. Parliamentary Boundary Commissions (one each for England, Scotland, Wales and Northern Ireland) undertake continuous reviews (and a general review every 8 to 12 years) to ensure that constituency population sizes remain balanced (approximately 70,000 electors (90,000 inhabitants) each). Boundary changes do not come into effect until the subsequent general election, but are based on the ward/division boundaries at the review date. Various (mostly minor) boundary changes were implemented to constituencies in South East England at the 2001 election but most constituencies still have their 1997 boundaries, which themselves reflect the wards as of the April 1995 review report*. There have been no name changes. The next general review is expected to be completed in late 2005 (deadline April 2007); thereafter the functions of the Parliamentary Boundary Commissions are to be taken over by the new Electoral Commission.
* Note: These amended constituencies will become the standard for statistical output by the end of 2001; for the time being however constituency-level outputs will continue to be produced to the 1997 boundaries.
The constituencies are distributed across the UK countries as follows:
||Number of constituencies/MPs
Note that on occasions constituencies may be described as either borough (burgh in Scotland) or county constituencies. Essentially, borough constituencies are entirely urban whereas county constituencies are partly or mostly rural. Definitions are allocated by the Boundary Commissions and affect candidates' election expenses and also who can be the constituency's returning officer; otherwise they have little impact. They also need not reflect whether the seat falls in an actual county or borough.
For information on coding and access to the Westminster parliamentary constituencies listing, click here.
This page last revised: Wednesday, 7 November 2001