When the Union of South Africa was formed in 1910, the electoral qualifications in use in each pre-existing colony were kept in place.

The first challenge to the Cape Qualified Franchise came with the Women's Enfranchisement Act, 1930 and the Franchise Laws Amendment Act, 1931, which extended the vote to women and removed property qualifications for the white population only – non-white voters remained subject to the earlier restrictions.

In 1936, the Representation of Natives Act removed all black voters from the common electoral roll and introduced three "Native Representative Members", white MPs elected by the black voters of the province and meant to represent their interests in particular.

Throughout its existence, it was located entirely within the southern suburbs of Cape Town, and like the rest of that region, its electorate was largely English-speaking, affluent and liberal.

Rondebosch was largely replaced by the recreated Claremont seat, which Slabbert stood for and won unopposed in the 1981 election.