Cameron unveils 'route to recovery'

But he promised the Conservatives would not embark on "slashing spending without regard to the social consequences" and declared: "Fiscal responsibility needs a social conscience or it is not responsible at all."

Mr Cameron's comments came in the first of a series of keynote speeches he plans to make setting out his "routemap to recovery" and on the day it was announced Britain's public debt had soared to £9bn.

He promised to tackle high salaries for bosses of public organisations, saying "the progressive Conservative approach means calling time on the culture of quango fat cats".

And he said the richest in society would have to "bear a fair share of the burden" in controlling spending so that the poorest did not suffer.

Mr Cameron, speaking in London, said: "We are not dealing with some average deficit, on a par with our peers. Just this morning, we saw the worst set of public finance figures in our peacetime history.

"According to some forecasters we are set to have the largest budget deficit of any G20 country this year. It could be more than 10% of our GDP.

"That is easily the biggest deficit since the Second World War - far larger even than when (Labour Chancellor) Denis Healey had to go to the International Monetary Fund in the 1970s."

However, Chief Secretary to the Treasury Yvette Cooper said: "How can David Cameron talk about fairness when he is still committed to a tax cut for millionaire's estates, won't back our £1.2bn help for the unemployed to get back into work, and wants to cut Sure Start?

"David Cameron's plans for cuts in apprenticeships, housing and transport in the middle of a recession are economic madness that would cost us all more in the long run."