BBC's James Cook: "It was literally a car crash event"
The launch of a new Labour poster campaign was interrupted by a car crash close to where cabinet members were giving their speeches.
The car smashed into a bus shelter on a traffic island in Hockley, Birmingham, as Business Secretary Lord Mandelson was speaking.
Police said the driver of the car was not injured.
Gordon Brown was telling supporters that he was "fighting not for myself, but for the future of this country".
After hearing of the crash, a spokesman for the prime minister said: "We are pleased no one was hurt."
The BBC's James Cook, in Hockley, said it appeared that a dustbin lorry had veered across a roundabout as the occupants shouted in the direction of the Labour event outside the New Bingley Hall community and conference centre.
A green Volkswagen Golf swerved to avoid to lorry and hit the bus shelter, our correspondent said, causing a loud bang and shock among the reporters and security staff gathered close to Mr Brown.
The Golf's driver, unemployed Omed Rashid, 27, said he would be voting Labour next Thursday.
Asked later by one broadcaster if the crash was a metaphor for Labour's election campaign, Lord Mandelson said: "No."
'Very last second'
Those gathered at the event alongside the prime minister and business secretary included Chancellor Alistair Darling, Deputy Labour leader Harriet Harman and Work and Pensions Secretary Yvette Cooper.
The posters show slogans like "Don't forget to vote Labour, Mum" and "Vote Labour, Gran" written in colourful, childlike writing. Another says "Vote Labour for us" and makes reference to Labour's pledge to protect child tax credits and the child trust fund.
As they were unveiled, Mr Brown told the audience he would fight until "the very last second" of the election campaign to secure a Labour victory.
The posters show slogans written in childlike handwriting
Snap polls suggest viewers felt Tory leader David Cameron was the winner in Thursday's third and final prime ministerial debate, but Mr Brown said "the Conservatives couldn't answer the questions".
"They couldn't explain what their policy was on inheritance tax other than that the wealthiest would benefit," he said.
"I think last night some of the great issues became clear. The time for the debates has past, but the time for decision is beginning."
Overnight viewing figures show that eight million people watched Thursday's debate at its peak, hosted by the BBC.
Mr Brown was also asked about a comment he made in his closing speech suggesting that without significant change over the coming week Mr Cameron or Mr Clegg could be the victor.
"What I actually said was if things stay the same way then the Conservatives and possibly the Liberals could be in government in a coalition together, and I want to point out the dangers of a Conservative victory, and I want to point out the dangers of the Conservatives going into coalition with the Liberals."
Mr Brown will be interviewed by Jeremy Paxman on BBC One at 2030 BST on Friday. David Cameron and Nick Clegg have both already faced similar interviews.
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