Mr Brown says the economy needs a boost now
Gordon Brown has again dismissed speculation about a summer general election telling the BBC he is "100% focused" on the economy.
Asked about reports he was considering a 4 June poll, the PM said: "You can just discount all these stories".
He also said "fiscal action" to stimulate the economy was needed "now".
Pressed on his claim to have ended boom and bust, he said politicians "made mistakes" but interest rates were much lower than they had been in the 1990s.
There has been speculation in the press that Mr Brown might call a general election in spring or summer 2009, with opinion polls suggesting Labour has narrowed the Tories' lead.
London's Evening Standard reports that Mr Brown is said to be "seriously considering" a 4 June date, to coincide with the local and European elections.
But the prime minister told BBC Radio 2's Jeremy Vine show: "My undivided attention is on the economy, I'm not thinking about anything else, it's 100% of my attention and you can just discount all these stories."
He added he was "not thinking about anything related to internal politics".
The prime minister also defended his plans to kick start the economy - tax cuts and public spending funded by extra borrowing are expected to be announced in the pre-Budget report on Monday.
"This is a situation where if you don't act now, and fiscal action is what we are talking about whether it is public investment or whether it is in taxation, we will pay for it later.
"You have got to act now so that we avoid a worse problem," he said.
He said those who "don't propose to take action now" were "making a very big mistake".
The Conservatives accuse Mr Brown of planning a "borrowing bombshell that will become a tax bombshell".
Asked why he claimed to have abolished boom and bust Mr Brown said: "I did get things wrong, obviously, of course politicians make mistakes and I've got to be honest, we have made mistakes."
But he said he had been talking about the economic problems of the Conservative-controlled early 1990s, when interest rates were 15%, whereas now there were a "different set of problems" - rebuilding confidence in the economy and getting the banks lending again.
Commenting on Brown's admission that he had made mistakes, shadow work and pensions secretary Chris Grayling said: "Gordon Brown certainly owes the British public an apology for racking up the highest borrowing this year for any major nation, for the 10p tax fiasco, for losing the child benefit database and for wrecking our pension system. Somehow I don't imagine that apology will be coming any time soon."
Mr Brown also suggested that state-owned bank Northern Rock may be changing its approach towards repossessions - in October it emerged the bank was repossessing 50% more properties than the industry average.
By the end of September, the state-owned lender had 4,201 seized homes, up from 2,215 at the end of last year.
Mr Brown told the programme: "We have been talking to Northern Rock about its practices and I think you will see some changes ... very soon."
Northern Rock has rejected suggestions that its approach to repossessions is "overly aggressive" and argues it is only ever used as a "last resort".