The ceremonial county of East Sussex (which includes the unitary authority of Brighton and Hove) is divided into 9 parliamentary constituencies: 4 borough constituencies and 5 county constituencies, one of which crosses the county border with West Sussex.
Under the fifth periodic review of Westminster constituencies, the Boundary Commission for England decided to retain the existing 8 constituencies in East Sussex, with minor changes to realign constituency boundaries with those of current local government wards, and to reduce the electoral disparity between constituencies.
See 2023 periodic review of Westminster constituencies for further details.
For the 2023 periodic review of Westminster constituencies, which redrew the constituency map ahead of the 2024 United Kingdom general election, the Boundary Commission for England opted to combine East Sussex with West Sussex as a sub-region of the South East Region, resulting in the creation of a new cross-county boundary constituency named East Grinstead and Uckfield. The resultant changes to existing constituencies entailed the abolition of Wealden and the creation of the new constituency of Sussex Weald. Brighton Kemptown was renamed Brighton Kemptown and Peacehaven, and, although its boundaries were unchanged, it was proposed that Hove be renamed Hove and Portslade.
The following constituencies were proposed:
Containing electoral wards from Brighton and Hove
Containing electoral wards from Eastbourne
Containing electoral wards from Hastings
Containing electoral wards from Lewes
Containing electoral wards from Rother
Containing electoral wards from Wealden
<sup>1</sup> Also contains part of Mid Sussex District in West Sussex
Primary data source: House of Commons research briefing - General election results from 1918 to 2019
The number of votes cast for each political party who fielded candidates in constituencies comprising East Sussex in the 2019 general election were as follows:
<sup>1</sup>1983 & 1987 - SDPâÂÂLiberal Alliance
<nowiki>*</nowiki> Included in Other
<sup>1</sup>1983 & 1987 - SDPâÂÂLiberal Alliance
A cell marked â (with a different colour background to the preceding cell) indicates that the previous MP continued to sit under a new party name.
The Local Government Act 1972 moved the District of Mid Sussex into West Sussex from East Sussex. This change was put into effect in the Parliamentary constituency boundaries for the 1983 boundary changes.
<sup>1</sup>partly in West Sussex