List of United Kingdom Parliament constituencies (1950–1974) by region

This is a list of all constituencies that were in existence at the 1950, 1951, 1955, 1959, 1964, 1966 and 1970 general elections, showing the winning party and broken down by region and county.

Middlesex (28 then 29)
With the exception of Spelthorne, which became part of Surrey, all of these constituencies became part of the county of Greater London when it was formed and Middlesex was abolished in 1965.

County of London (43 then 42)
The county of London was abolished in 1965 and became part of the much larger county of Greater London. See https://commons.wikimedia.org/wiki/Category:Locator_maps_of_former_parliamentary_constituencies_of_England_1948

Cambridgeshire and Isle of Ely (3)
The separate administrative counties of Cambridgeshire and Isle of Ely were combined in 1965.

Northamptonshire and Soke of Peterborough (5)
The administrative county of the Soke of Peterborough was combined with Huntingdonshire in 1965 to form Hundingdonshire and Peterborough.

Fermanagh and Tyrone (2)
1The constituency was won by Philip Clarke of Sinn Féin, but he was unseated on petition on the basis that his criminal conviction (for Irish Republican Army activity) made him ineligible. Instead, the seat was awarded to the Ulster Unionist Party (UUP) candidate.

2The seat was originally won by Tom Mitchell of Sinn Féin, but Mitchell was subsequently unseated upon petition, on the grounds that his terrorist convictions made him ineligible to sit in Parliament. The seat was awarded to Charles Beattie of the UUP. However, Beattie in turn was also found ineligible to sit due to holding an office of profit under the crown, triggering a further by-election.