Brown and Darling were encouraged by initial poll projections that the new top rate was popular with more than half the electorate.
But a separate poll for the Politics Home website showed 53% of those polled not believing the chancellor's economic forecasts that growth will surge back to 1.25% next year and 3.5% in 2011. Lord Mandelson, the business secretary, pleaded with the electorate to judge the government's budget decisions and the recovery in a year's time.
"There has got to be a contribution by those who have the most, and who have gained the most over the last few years," he said."This is not taxation for its own sake, it is tax for a purpose.
It shows what a dishonest budget it was and how quickly it is unravelling."Britain has moved from the age of prosperity to an age of austerity, but the leadership of the Labour party has been completely left behind by events.
Robert Chote, the institute's director, said that by 2017-18 the loss through tax increases and cuts in public spending would be equivalent to £2,840 a year for every family in the country - only half of which has been accounted for by the government.
The IFS calculated that there is a £45bn black hole in the finances, requiring a further tax rises of £1,430 per family, or massive spending cuts.
Alistair Darling accused of 'tax bombshell' as thinktank warns of massive cash gap Ministers will be forced to make the most savage spending cuts since the 1970s, a respected economic thinktank predicted yesterday, confounding Alistair Darling's attempt to deflect claims that his budget has ushered in a decade of austerity.
The Institute for Fiscal Studies warned that even big spending cuts in health and schools may not be enough to fill the structural deficit in the nation's finances.
"Health, education, law and order would all experience real cuts."Chote said it looked likely that the bulk of the savings required over the coming eight years would mainly come from spending cuts rather than new taxes."The main burden of the looming tightening - at least over the next few years - is likely to fall on the users of public services," he said.