Britain must keep supporting the economy for now, and the Conservatives are wrong to talk down the country by warning it could lose its triple-A credit rating, Prime Minister Gordon Brown told Reuters.

Interviewed flying back from an EU summit in Brussels late on Thursday, Brown set out his stall for an election expected on May 6 where he is very much the underdog. He argued only his party stands for middle-class Britons, has made the right calls on the economy and can be an effective voice in Europe.

He said he expected economic growth in Q4 2009 to be revised higher from the 0.1 percent estimate published last month but that the recovery was still too fragile to cut spending just yet, as advocated by the Conservative Party.

"It is clear that in a fragile recovery and an uncertain world -- because that is what we are living in -- we do not withdraw the help we are giving to the economy," he said. "My policy is to go for growth."

After an 18-month recession that wiped out 6 percent of output, the budget deficit is expected to hit a record high above 12 percent of GDP this year.

Shadow Chancellor George Osborne warned last week that Britain could suffer a credit downgrade and Greek-style debt crisis if more action was not taken to cut the deficit.

Brown categorically dismissed this.

"People will have to judge for themselves how responsible the opposition party is being. I think that talking down Britain at any time is unfair and wrong," he said.

Brown said the average maturity of UK debt was 13 years, much higher than many of its peers. Not being part of the euro also gave Brit ain more flexibility, he said.

"We have set what is probably the most ambitious deficit reduction plan in the G7. We have said we will halve the deficit over four years," he said.

"We have made it clear to people that there are changes that will happen, to public sector services, to public sector pay, to public sector pensions that will make it possible for us to deliver a high level of service while at the same time achieving reductions in expenditure."

Labour's plans to cut the deficit only start next year. The Conservatives have said this is too late, promising an emergency budget within 50 days of taking office if elected.

NARROWING POLLS

Recent opinion polls have shown the Conservatives' once commanding lead shrinking to single digits, pointing to the possibility of a hung parliament where no party wins a majority.

Asked if that was the best he could hope for, Brown, prime minister since 2007 and chancellor for a decade before, said: "I am never complacent but we are fighting for victory."

The Conservatives, Brown said, had nothing to say about the future and were light on policy substance.

"The Conservatives have got everything wrong about the recession ... Every time they have had to make a judgement they have been wrong. I think the public are beginning to see through the Conservative Party -- that their judgement is an issue."

Labour, he argued, had worked hard to keep unemployment low and home repossessions down compared with the recessions of the early 1980s and 1990s when the Conservatives were in power.

"It was always the case until the recession is over, people would suspend judgement, but now they are faced with a choice, people will make up their minds," Brown said.

EU RELATIONS

Europe, he said, was another key dividing line. Conservative leader David Cameron has pledged to try to claw back some powers from the European Union and has also withdrawn from the mainstream centre-right group in the European parliament.

Brown said: "Our membership of the EU, being at the centre of the EU, is not just very important for our economy but for climate change.

"And for the opposition Conservative Party to be completely on the fringes of Europe -- to not even have a relationship with Germany's Christian Democrats or the French party led by President (Nicolas) Sarkozy -- is a terrible mistake," he said.