The shortlist of Labour candidates for the Lewisham East by-election in June is made up of only black and ethnic minority women, the BBC understands.
Either Janet Daby, Brenda Dacres, Sakina Sheikh or Claudia Webbe will be picked to run as the party's candidate for the by-election on 14 June.
The vote was sparked by the resignation of Heidi Alexander who is going to work for Sadiq Khan.
The winner will be selected by Labour members in Lewisham East on Saturday.
Ms Alexander won the south-east London constituency by more than 21,000 votes in last year's general election, with the Conservatives second and Liberal Democrats third.
She is to become London's new deputy mayor for transport.