David Cameron said economic confidence was badly needed
A Conservative government would not make "swingeing cuts" to public spending during its first year, party leader David Cameron has said.
But he told the BBC it was right to "make a start" on cutting the deficit, to avoid leaving the UK with the same "scale of problems" as Greece.
But Prime Minister Gordon Brown warned it was important not to "pull the rug" from the economy.
The budget deficit for this year is forecast to grow to £178bn.
Figures released last week show that the UK economy came out of recession in the final quarter of 2009, but with a weaker than expected growth of 0.1%.
'We are serious'
The scale of government debt is becoming one of the key issues in the lead-up to the general election.
Labour says cutting spending now will damage the recovery, while the Tories argue that too much debt could imperil it.
The Lib Dems say they are proposing £10bn more spending cuts than the government and Treasury spokesman Vince Cable has warned that "the consequences of failure to bring the deficit under control are serious".
Outlining his party's plans, Mr Cameron told BBC One's Politics Show: "We're not talking about swingeing cuts. We're talking about making a start in reducing our deficit."
He added: "You've got to make a start. Look, if we have an election in May, your year is already under way.
"You've got to make a start, we believe, in proving we're serious about getting this deficit down.
"And those who say you're taking money out of the economy, I would say, if you don't do this, even more money could be taken out of the economy in two ways.
"One, because interest rates could go up as they have done in Greece. Secondly, money gets taken out of the economy because there isn't the confidence there and it's confidence we need so badly.
"People want to see a government that is taking decisions on a five-year horizon rather with this government taking things on a five-week or, some say, even five-minute horizon."
'Albatross of debt'
Mr Cameron did not give a projected figure for cuts to public spending, but promised to work with the Bank of England to "make sure we keep low those interest rates".
He added: "What year one [of a government] has to have is a start to cutting the public spending programmes.
"But it should be done in conjunction with the monetary policy authorities because we want to make sure that those interest rates remain low."
Appearing on the BBC's Andrew Marr Show, shadow chancellor George Osborne said "early action" was needed on the deficit to avoid a "Greek-style budget crisis".
He insisted that it would be a "mistake" to wait until next year to begin tackling the "albatross of debt", as the government was planning to do.
However, Mr Brown used his weekly podcast on the Downing Street website to warn that the economy still needed support and that cutting too soon risked tipping it back into recession.
He said: "Return to strong, sustainable global growth is still some way off. So I can reassure you that we are not about to jeopardise Britain's economic future by suddenly pulling the rug from under the recovery.
"We will continue with the measures we have put in place that are supporting families and businesses and we will continue to invest willingly and whole-heartedly in this country's future - and I will make no excuse for that.
"Only with this radical approach and a plan for prosperity for all can we deliver renewed growth, jobs and opportunities for all."
Speaking on The Politics Show, Business Secretary Lord Mandelson said: "It is talking Britain down when David Cameron compares Britain ludicrously in everyone's eyes to Greece, and when George Osborne describes Britain as an exhausted runner at the back of a long marathon race unable to summon the strength to build our economy.
"That is disgraceful. It is irresponsible. It's also unpatriotic."