Boundary changes for the United Kingdom general election, 2010

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 British Parliament. The changes to constituencies from three reviews were approved and took effect at the 2010 United Kingdom general election; that for Scotland took effect at the 2005 election.

The boundary commissions were required at the time by the Parliamentary Constituencies Act 1986 to review constituencies in their part of the United Kingdom every eight to twelve years. A Commission's recommendations from a review are based on the numbers of electors on the electoral register at the start of the review.

In Scotland, the recommendations were submitted in November 2004, and approved in February 2005. In Wales, the recommendations were submitted on 31 January 2005, and approved on 11 April 2006. In England, the recommendations were submitted on 31 October 2006, and approved on 13 June 2007. In Northern Ireland, the recommendations were submitted on 14 September 2007 and approved on 11 June 2008.

In England, the seats recommended by the commission generally do not cross boundaries of the largest local authority areas, i.e. counties (metropolitan or otherwise); however they may cross boundaries of unitary authority areas. York, for example, was consolidated into two constituencies, without electoral wards from North Yorkshire, whereas the unitary authorities of Berkshire have many cross-authority seats.

Some areas of England were awarded extra constituencies in the review, including Lancashire and Essex. Other review areas had one constituency removed, such as Tyne and Wear. Greater London as a whole was reviewed on a borough-by-borough basis, with two areas losing one constituency and central London gaining a constituency.

...
Wikipedia