"If there's a mistake made, it's my fault and I accept the responsibility," the Prime Minister told GMTV.
Despite the negative pre-poll indications, Brown insisted thousands of people will not yet have decided how to vote and that Labour still has a chance in the Thursday's general election.
But asked if he personally would be to blame if they are routed, he said: "I'll have to take responsibility and I will take full responsibility if anything happens".
Pushed on whether he would stand down for the good of the party, Brown said: "I don't think it will work that way but if I couldn't make a difference any more then I would go off and do something else."
Brown dismissed the prospect of following in his predecessor Tony Blair's footsteps and going into business once he leaves Number Ten (10 Downing Street), saying he and his wife both wanted to do charity work.
"Sarah and I may go off and do charity voluntary work. I don't want to do business or anything else, I just want to do something good," he said.
He insisted that after "all these debates" and "novelty", the vote would still come down to the central issues like the economy and the National Health Service.
"Conservatives are too big a risk. Liberals, well they can't explain what they're doing, they don't add up," he said.
"We're the serious party, maybe too serious sometimes, but we're the serious party with serious policies for the future, and I want to get that across," the embattled premier said.
He said he has no regrets about "the election that never was" in 2007, when he may easily have won and had five years as a properly-elected PM.
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