Veteran MP and former minister Michael Meacher has launched a challenge to Gordon Brown for the Labour leadership, promising a left-wing agenda.
Mr Meacher said Britain needed a new foreign policy, not "subservient" to the US, and to raise the minimum wage.

Mr Meacher claims to have support from enough MPs to get on to the ballot and insisted he had a chance of winning.

Fellow left-winger John McDonnell, who has planned his own leadership bid for seven months, said he would fight on.

"We have been expecting Michael's announcement for over nine months. It doesn't change things," said Mr McDonnell.

Since being sacked as an environment minister in 2003, Mr Meacher has been critic of the government.

'Proper debate'

Announcing his intention to stand on Thursday, he said: "We need a new foreign policy which is based on fundamental British interests, not subservience to the US.

"It is not sustainable to continue as America's glove puppet. Domestically, we should start by raising the national minimum wage quickly to six pounds an hour and soon after to seven pounds an hour."

Mr Meacher, one of Labour's longest-serving MPs, was environment minister between 1997 and 2003.

Since leaving the government he has criticised Chancellor Gordon Brown, the favourite to take over from Mr Blair, for signalling he would renew Britain's nuclear weapons system.

He has said there had to be " proper debate" about Trident, if not a referendum on the issue.

And he has been an outspoken critic of British foreign policy, as well as a passionate campaigner for more robust action on climate change.

Mr Meacher has told the BBC he is confident he can get the backing of the 44 MPs needed to get on to the ballot.

But Labour MP Stephen Pound said Mr Meacher was a "faintly ridiculous" figure, adding he would be surprised if the veteran left-winger managed to get the required support.

Contest not coronation

"It's a pity because, frankly, he's going to get humiliated," said the Ealing North MP.

"I suspect he knows that, if he put his ego to one side a bit he would realise that.

"Michael Meacher is a major figure on the British political scene, yet the majority of people I have spoken to, who came into Parliament in the last six or seven years, just said: 'Who?' They didn't know who he was."

BBC political editor Nick Robinson said some Labour MPs would welcome a contest and Gordon Brown himself might prefer a contest to a "coronation", as it would give his leadership more of a mandate.

But he said the Conservatives were bound to use the news to argue that the Labour leadership - and deputy leadership - contests represented a further move to the left for the party.

Constitutional Affairs Minister Harriet Harman, a contender for the deputy leadership, welcomed the prospect of a full-blown leadership contest.

'No bad thing'

She told BBC Radio Berkshire: 'It's the Labour members, the Labour Party members' right to vote for the new leader and deputy leader.

"And although there is overwhelming support for Gordon Brown and I myself strongly support Gordon Brown and I will be nominating him, I think actually a contest is no bad thing."

Mr McDonnell, who will be competing with Mr Meacher for left-wing Labour backing, said he had the support of about 22 MPs, and would not drop out of the race.

He said: "Labour Party members will still have the same choice between my record of voting against the war in Iraq, voting against tuition fees, voting against privatisation of our public services and cuts in benefits and the record of those ministers and former ministers like Gordon Brown and Michael Meacher, who have consistently voted for these policies."

There has been speculation a senior figure from the Blairite wing of the party, such as Home Secretary John Reid or Environment Secretary David Miliband would mount a leadership bid.

But so far no heavyweight contender has emerged to challenge Mr Brown.