South West Hertfordshire is a constituency in the House of Commons of the UK Parliament, represented since 2019 by Gagan Mohindra, a Conservative.

Constituency profile

Since the 2024 United Kingdom general election, at which major boundary changes instigated by the 2023 Periodic Review of Westminster constituencies took effect, this seat has consisted of the entirety of the Three Rivers District, plus the single ward of Kings Langley from the Dacorum district. The constituency surrounds the constituency (and town) of Watford on three sides, taking in the town of Rickmansworth and the villages of Abbots Langley, Chorleywood, Croxley Green, Heronsgate, Kings Langley, Leavesden, Loudwater, Maple Cross and South Oxhey. Elevated and bordering Greater London and Buckinghamshire, this part of Hertfordshire is for its residents mostly middle-class suburbia, an established haven for commuters who travel from the outer reaches of the London Underground's Metropolitan line or two railways from London which serve different parts of the seat: the West Coast Main Line and Aylesbury Line. Much of the constituency is within the Greater London Built-up Area, though it also contains Green Belt land.

Boundaries and boundary changes

1950–1974

''The constituency was formed from the Watford Division of Hertfordshire, excluding the part comprising the Municipal Borough of Watford. It also included the parishes of Abbots Langley and Sarratt, transferred from Hemel Hempstead.''

1974–1983

The parish of Aldenham in the Rural District of Watford was transferred to the new constituency of South Hertfordshire.

1983–1997

''The parts of the District of Dacorum, including Berkhamsted, were transferred from the abolished constituency of Hemel Hempstead. Abbots Langley was transferred to Watford and Bushey to the new constituency of Hertsmere.''

1997–2010

''Gained Tring from the abolished constituency of West Hertfordshire. Kings Langley transferred to a re-established Hemel Hempstead, Bedmond to St Albans, and three further wards in the Three Rivers District to Watford.''

2010–2024

Minor gain from Hemel Hempstead following revision of local authority wards.

Current

Further to the 2023 Periodic Review of Westminster constituencies, which came into effect for the 2024 general election, the composition of the constituency is as follows (as they existed on 1 December 2020): The constituency saw major changes with the bulk of the portion of the previous iteration of seat in the Borough of Dacorum, including the towns of Berkhamsted and Tring, forming part of the newly created constituency of Harpenden and Berkhamsted. The Bovingdon, Flaunden and Chipperfield ward went to Hemel Hempstead in exchange for the Kings Langley ward. The parts of the District of Three Rivers not previously within the constituency were transferred primarily from Watford, with a small area from St Albans. Only 55% of the electorate of the former constituency remained in the redrawn seat, and only 63% of the redrawn seat's electorate came from the previous version of the constituency

Members of Parliament

Watford prior to 1950

Elections

Elections in the 2020s

Elections in the 2010s

Elections in the 2000s

Elections in the 1990s

Elections in the 1980s

Elections in the 1970s

Elections in the 1960s

Elections in the 1950s