Chris Hanretty, the Professor of Politics at Royal Holloway, estimated that Eastbourne voted 57.6% to 42.4% in favour of leaving the European Union during the 2016 referendum.

With the exception of the landslide Liberal victory in 1906, the seat returned Conservative Party candidates at every election from its creation in 1885 until 1987.

Although it was recaptured by the Conservatives at the subsequent general election in 1992 and held until 2010, it became a marginal, or swing seat, from 1990 onwards, being closely fought for between the two locally dominant parties.

1950–1955: The Boroughs of Eastbourne and Bexhill, and in the Rural District of Hailsham the parishes of East Dean, Friston, Hooe, Jevington, Ninfield, Pevensey, Polegate, Wartling, Westham, and Willingdon.

1974–1983: The Borough of Eastbourne, and in the Rural District of Hailsham the parishes of East Dean, Friston, Jevington, Pevensey, Polegate, Westdean, Westham, and Willingdon.

[2] In order to bring its electorate within the permitted range, the parts within the District of Wealden were transferred to the Lewes constituency.