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Parliamentary constituencies

The United Kingdom is currently divided into 650 parliamentary constituencies. One Member of Parliament (MP) in the House of Commons represents a single constituency.

There are currently:

  • 533 constituencies in England
  • 59 in Scotland
  • 40 in Wales
  • 18 in Northern Ireland.

The number of people able to vote (the electorate) differs by constituency. The Office for National Statistics gives the average electorate across constituencies of about:

  • 72,200 in England
  • 67,200 in Scotland
  • 68,300 in Northern Ireland
  • 56,000 in Wales

The largest constituency is Ross, Skye and Lochaber.  It measures approximately 12,000 square kilometres.

The smallest constituency is Islington North at 7.35 square kilometres.

Boundary commissions review boundaries. There are four commissions:

Commissions recommend changes to boundaries about every 5 years. Changes may be due to changes in population or local government boundaries.

Both Houses of Parliament need to agree any changes. 

The House of Commons Library has data to help you understand more about your constituency


Image: iStock

Find my constituency

Related information

The United Kingdom is currently divided into 650 parliamentary constituencies, but this has not always been the case. Find out about how the number of seats in the House of Commons has changed.