Labour's deputy leader contenders are split on the idea of shortlists made up only of people from ethnic minorities.
The deputy leader will be announced on 24 June
Hazel Blears, Jon Cruddas and Peter Hain told a hustings event in Leicester they backed such lists to boost the numbers of black and Asian MPs.
Alan Johnson and Hilary Benn said they were not persuaded. Harriet Harman did not say whether she backed them or not.
The hustings was attended by 400 Labour members, mostly from ethnic minorities. Of 646 MPs, 15 are black or Asian.
Women-only shortlists have been used in the past by Labour to increase the numbers of women selected as candidates for Parliament, but they have proved controversial and faced legal challenges.
Education Secretary Mr Johnson said the lack of ethnic minority MPs was a "scandal", but thought the shortlists would be a form of discrimination.
"I'm not totally convinced by BME (black and minority ethnic) shortlists.
"But what you can do is that if a community has 25% to 40% of people from ethnic minority backgrounds we ensure that the shortlist for candidates reflects that."
International Development Secretary Mr Benn said he was "yet to be persuaded" that shortlists were the answer while Justice Minister Ms Harman said there needed to be four times as many ethnic minority MPs, but did not confirm whether she backed shortlists or not.
But Northern Ireland Secretary Mr Hain, who was an anti-apartheid campaigner, said: "We have got to get more candidates from ethnic minorities selected.
"That does, I believe, involve positive action and all-black and ethnic minority shortlists."
Party chairwoman Ms Blears said "practical action" was needed and said Labour's ruling NEC could draw up plans to move towards shortlists.
And backbencher Mr Cruddas said it was "inevitable" that Labour would move towards shortlists in certain cases.
Recently Culture Minister David Lammy called for Gordon Brown, who will succeed Tony Blair as prime minister, to consider imposing ethnic minority shortlists.
The Lib Dems, whose only ethnic minority MP lost his seat at the last election, are also considering plans to recruit more members from ethnic minorities.
The Conservative Party's controversial "A list" of candidates was designed to ensure more women and ethnic minority MPs were selected as candidates in winnable seats.
But it proved controversial with some local associations, who preferred local candidates.
And while Labour led the way with all-women shortlists, they too proved controversial.
The late Peter Law quit the party in protest and ran as an independent in Blaenau Gwent in 2005 - overturning a 19,000 Labour majority to win.