Gordon Brown has attempted to play down a slip of the tongue in which he said the government had "saved the world".
The gaffe, during House of Commons exchanges over the economy, provoked howls of laughter on the Tory benches.
Mr Brown had meant to say ministers had "saved the banks and led the world" on tackling the downturn.
His spokesman later gave the more usual government line that the PM had been "reflecting on helping hardworking families through the downturn".
Mr Brown's verbal faux pas, uttered during prime minister's questions, came in response to criticism of his handling of the banking crisis.
To uproar from the opposition benches, he said "we not only saved the world, er, saved the banks and led the way..." before being drowned out by laughter.
The Speaker repeatedly had to shout "Order", as Tory MPs waved their papers, punched the air and jeered.
After the mood in the chamber calmed down, Mr Brown said: "The opposition may not like the fact that we led the world in saving the banking system, but we did."
As the prime minister sat down, a biblically minded MP mockingly shouted: "Moses."
'Forgotten about businesses'
Tory leader David Cameron then got up to speak, saying: "Well, it's now on the record.
"He's so busy talking about saving the world, he's forgotten about the businesses in the country that he's supposed to be governing."
The prime minister, whose gaffe is already an internet hit, managed a smile.
The mistake comes at a time when Mr Brown is travelling to summit after summit in an effort to persuade fellow world leaders that his "fiscal stimulus" policies should be repeated.
Some detractors have jokingly compared him to the fantasy film hero - and partial namesake - Flash Gordon, who rescued earth from attack by Martians.
That followed the marketing push from the early days of his premiership when he was promoted under the slogan Not Flash, Just Gordon.
Asked at a government briefing later whether Mr Brown had meant to say he had saved the world, his spokesman said: "The prime minister has been reflecting on helping hardworking families through the downturn."
Tory MPs punched the air after Mr Brown's comments
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