Labour agrees to extend leadership bids deadline

The original May 27 deadline to secure the backing of the 33 MPs needed to get on the ballot paper has been moved back until June 9 after complaints, including vocal opposition from left-wing backbencher John McDonnell who had accused the party of acting undemocratically.

The MP, who chairs the Socialist Campaign Group, failed in an attempt to secure enough nominations in 2007 to mount a challenge to Gordon Brown's uncontested succession to the leadership.

Former Health Secretary Mr Burnham became the fourth ex-Cabinet minister to declare he wanted to succeed Gordon Brown after brothers David and Ed Miliband and Ed Balls.

In an opening salvo, he promised an end to "stage-managed" politics run by "elites" and the creation of a "People's Party". "We must become a new kind of Party that involves and consults its members on a daily basis – truly a People's Party – and reduces the influence of small elites at the top," he insisted.

And at a formal leadership bid event at the People's History Museum in Manchester, he declared: "The party is my life, Labour is my passion.

"It's a big step but one I'm ready to take. I have served the party for 25 years at every level, as a member, nine years as a Member of Parliament for the area I grew up in and five years as a Government Minister in some of the most demanding jobs in the Government."

In a surprise move, Ms Abbott became the first female runner and said she was confident of attracting the required support.

The Hackney North and Stoke Newington MP, who became the first black woman MP in 1987, said: "The Labour movement has changed, the majority of members of our big industrial unions are women, we need to talk directly towards women and women workers.

"And we need to accept, in a way that past ministers cannot accept, what we did wrong in the past 13 years."