Labour activists have overwhelmingly endorsed a radical package of internal reforms which the party hopes will make it easier to win widespread support in the wake of last year's electoral bloodbath.
Registered Labour supporters who are not members will now be eligible to take part in leadership elections in an effort to make the party more open. Nearly 94% of activists supported the changes; the remaining 6% objected.
During a speech to the Labour Party Conference in Liverpool on Sunday, former Cabinet minister Peter Hain, who led the Refounding Labour project, told delegates the changes would allow the party to sign up thousands of new supporters in the same way Barack Obama managed to garner popular support in the 2008 US presidential election.
Ken Livingstone was already mimicking the model successfully ahead of next year's mayoral election in the capital, he said.
Mr Hain added: "We will reach out to potentially hundreds of thousands of Labour supporters - people who wouldn't join, but who could be registered as supporters.
"That's what Barack Obama did to win in 2008 - created a people's movement amongst those who never saw themselves as party animals but were with him and were vital to his victory. That's what Ken is doing in London. This is what we mean by Refounding Labour. Registering thousands of new supporters is a huge opportunity, not a threat."
The party was urged to learn lessons from the way its activists defeated the British National Party (BNP) in council elections last year.
Senior MP Margaret Hodge told delegates "fundamental change" was needed - and demanded the party follow the example set by Labour campaigners in Barking and Dagenham which helped rout the BNP last year.
Mrs Hodge blamed Barking Labour's previous regimes for allowing the far-right BNP to generate support - even branding it racist for its refusal to field black and Asian candidates in white areas for fear of alienating voters.
She said: "We triumphed because we changed - and now Labour faces a huge challenge to regain the trust of voters across the country. Our party has to reconnect with their priorities and their values, just as we have started to in Barking. Only then will Labour triumph nationally, only then can Labour really win."