Four hopefuls have put forward their names to be the Labour candidate in the 2012 London mayoral elections.
Former mayor Ken Livingstone and former Bethnal Green MP Oona King are in the running, along with party activists Seton During and Emmanuel Okoro.
Mr During is a chartered engineer and a former councillor in Enfield, while Mr Okoro is an artist.
A panel of party representatives will confirm the shortlist on 24 June, with the result due on 24 September.
That is the day before the party reveals who has won the race to succeed Gordon Brown as its leader.
The mayoral candidate will be picked by an electoral college, made up half-and-half of votes from London party members and members of affiliated organisations.
Mr Livingstone was the city's first elected mayor, between 2000 and 2008, before being ousted by the Conservative Party's Boris Johnson.
Mr Livingstone was an Independent in his first term as mayor, following his defeat of Labour candidate Frank Dobson.
He ran against Labour amid claims the party machine had deliberately sought to prevent him from winning the nomination.
He returned to the Labour Party to win his second term in office in 2004.
Mr Livingstone launched his campaign to be Labour's 2012 mayoral candidate on 1 June, criticising Mr Johnson's transport policy.
Ms King was the MP for the east London seat of Bethnal Green and Bow between 1997 and 2005, when she was defeated by George Galloway of Respect.
Her decision to vote for the Iraq War was seen as central to her losing the seat, which has a large Muslim population.
Ms King launched her campaign to be the next Labour London mayoral candidate on 26 May, promising to be an "advocate for children".
Mr During said he had 20 years of sea-going experience as a chartered marine engineer, and had served as a councillor for Ponders End on Enfield Council from 1990 to 1994.
If elected as mayor, he promised to "improve the qualities of life and wellness for all Londoners".
And he said he would work with residents, companies, youth groups and organisations representing politics and business.
Mr Okoro could not be reached for comment.