In a surprise move, the Labour MP for Hackney North and Stoke Newington said she was confident of attracting the 33 nominations needed to get her on to the ballot paper.
She becomes the sixth participant in the contest, after David Miliband, Ed Miliband, Ed Balls, John McDonnell and Andy Burnham.
Abbott told BBC Radio 4’s Today programme this morning that she wanted to open up the field because she did not feel there was “a lot” between the candidates who had thrown their hats in the ring so far.
Abbott is a member of the parliamentary leftwing group of Labour MPs, Campaign, which is chaired by McDonnell.
There had been concern in the party at the lack of a female challenger to take over from Gordon Brown as Labour leader.
Harriet Harman and Yvette Cooper have said they will not stand.
Abbott, who doubled her majority at the general election, insisted her bid was “perfectly serious”. “I’m going to run,” she said, announcing her bid on Radio 4. “So many people in the past 48 hours have asked me to put my hat in the ring and I have finally decided to do so.”
Abbott said Labour needed the “broadest possible” contest as it debated the future of the party after this month’s general election defeat. “We can’t go forward with a leadership debate where there is no woman,” she said.
Abbott, the daughter of Jamaican immigrants, said that none of the current frontrunners in the race would admit that the immigration system is “still inefficient and unfair and brings abuse, but nobody will say we have to address the underlying issues behind black and white working class unease about immigration, about housing, job insecurity.
“And, you know, if we are going to have a debate about immigration, I am the child of immigrants. Don’t the millions of British people who are the children of immigrants have a voice in this debate also? I could not be more serious.”
Abbott, who in 1987 was the first black woman to be elected to parliament, was publicly urged to stand yesterday by Simon Woolley of Operation Black Vote.
Woolley wrote yesterday that “without any women of stature standing, the leadership challenge becomes a poor portrayal of a party that has campaigned so long for women’s rights, but has not empowered them sufficiently for one of them to stand.
“Another glaring omissions is long-term experience, not just as a party member or as an MP, but also – and this is critically important – as a long-standing community campaigner.
“Diane Abbott bridges all these gaps and more, including race equality and frontline trade union experience.”
Abbott has sat on the backbenches throughout the last 13 years of a Labour government but has attracted public recognition through her weekly appearances alongside the former Conservative politician and media personality Michael Portillo on the BBC’s weekly politics show This Week.
Her leftwing credentials were dented in 2003 when she decided to send her son to the private £10,000 a year City of London school, after previously criticising Tony Blair and Harriet Harman for sending their children to selective state schools.
Abbott threw her hat in the ring on the same day as Andy Burnham, the former health secretary, launched his bid for the Labour leadership with a pledge to create a “People’s Party”.
In an article for the Daily Mirror, Burnham said he would put an end to “stage-managed” politics run by “elites”.
Burnham insisted he could be a “unifying” force for the party, suggesting that – unlike most of his rivals – he had never taken sides in the Blair-Brown infighting.
“I am a team-player; I’ve never had time for factions,” he wrote.
“That’s why I can help make Labour welcoming and unifying, a voice for all people who want to get on in life but also want to live in a country fair to all – with a more even spread of health, wealth and life chances.”
The Leigh MP said Labour had to “open up to more people”.
“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.
“We should bring down the final curtain on the era of stage-management in politics, making our party conference a forum for real debate and drama once again.”