LABOUR will lose the next London mayoral election if its candidate is a "glass puppet for the party machine," Diane Abbott yesterday told the Star as she prepared to announce her candidacy for mayor.

The firebrand left-winger will make "a firm declaration of intent" to delegates at Labour's London regional conference tomorrow.

She joins transport journalist Christian Wolmar, Tottenham MP David Lammy and former new Labour minister Dame Tessa Jowell in the contest.

And in an exclusive interview with the Star, Ms Abbott set out her vision for a progressive capital - hitting back at Ukip-lite immigration policies and making the case for a radical housing strategy.

She also favours devolving more powers to London and freezing bus and Tube fares.

A poll published in the London Evening Standard on Thursday put Ms Abbott just two points behind frontrunner Ms Jowell among Labour voters.

But in comments many will see as a shot at Ms Jowell and fellow MP Sadiq Khan, thought to be the party leadership's choice, Ms Abbott said: "London is a bastion of progressive politics, and it's important that it continues to be so.

"Londoners take it very seriously - they want a genuine independent, not a glass puppet for the party machine."

"I'd like to see some money raised by the mansion tax go to helping key workers with mortgages. And I'll be campaigning for some form of rent controls," she said.

Mr Wolmar, who declared his candidacy two years ago, said he would "agree with many of these proposals," and welcomed Ms Abbott's declaration.

But he criticised the party managers' decision to keep the debate to just six weeks following the general election.

Ms Jowell did not respond to requests for comment.

Asked if she would favour the old system where Labour's London conference drew up the manifesto, Ms Abbott said: "I'd like to see London Labour members play a bigger role in drawing up the London manifesto, given they're the people we expect to sell it on the doorstep."

Hopefuls were due to debate "the future of London" at a conference session on Sunday - but this was unexpectedly cancelled this week. A source close to the selection told the Star they believed "Sadiq intervened as he didn't want other candidates getting a platform."

Mr Khan will himself make a keynote address at the conference.