The opposition party has said public spending cuts should start now to address the budget deficit which is expected to reach £175bn by the end of the financial year. Tory leader David Cameron has said the government is "losing control of the nation's finances".
But Mr Brown told Sky News: "All the evidence internationally is if we hadn't put the stimulus in we couldn't have had anything like the prospect of returning to the growth that we have at the moment."
He also warned against shutting down the global "fiscal stimulus" programmes - which are shoring up the global economy with a trillion dollars of government money - too soon: "We don't yet have a recovery. The recovery is not automatic."
The G20 had to make sure the recovery was "certain" and work together to ensure "sustainable long term growth", he added.
Writing in the Times on Friday, former Labour deputy leader Lord Hattersley said these were "desperate days" for Labour, but defeat was not inevitable.
He also warned any would-be leadership challengers that any attempt to force out Mr Brown "would produce a bloodletting that makes defeat certain". Instead, he urged Mr Brown to speak "at last about freedom and equality" to win over voters.
Sadiq Khan predicts 'a difficult conference'
Transport minister Sadiq Khan told BBC 2's Daily Politics it would be a "difficult conference", the last before the general election, but that Mr Brown was the right man to lead the party.
"We as a party should make sure that next week we show the country it is not a referendum on how perfect or imperfect Gordon Brown or the government is, it's a choice between our party and the Conservative Party," he said.
"This week we saw Henry Kissinger giving Gordon Brown the award for the best statesman over his performance over the last 12 months on the world economy - the problem we have is translating that message domestically.
"We will see over the next few weeks and months us going down the road to recovery - the important question the electorate should ask themselves is, would we be as far down this road to recovery had Gordon Brown and Alistair Darling not had the policy they had to take us through this?"
This week Charles Clarke, the former home secretary and a long-time critic of Mr Brown, said in an interview Labour could be "hammered" at the general election and out of power for 10 to 15 years.
He said Mr Brown had convinced himself that voters would eventually reward him for getting Britain through the recession - but suggested he should quit before the election.
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