Its first Member of Parliament (MP) was former Prime Minister Edward Heath, who previously represented Bexley (1950–1974) and Sidcup (1974–1983).

Sir Edward Heath (Prime Minister of the United Kingdom 1970–1974) held this area (also referring to its main predecessor seats, Bexley and Sidcup) from 1950 until 2001 when he retired at the age of 84, at the time the longest-serving MP in the Commons, known as the Father of the House.

2010–2024: The London Borough of Bexley wards of Blackfen and Lamorbey, Blendon and Penhill, East Wickham, Falconwood and Welling, Longlands, St Mary's, and Sidcup.

As its name suggests, the seat covers the Bexley and Sidcup areas; it formerly included Danson Park which owing to more development in the south was moved to the Bexleyheath and Crayford constituency.

Boundaries were extended slightly by adding the parts of the expanded East Wickham and Falconwood & Welling wards previously in Bexleyheath and Crayford.