Ed Balls has revealed that Labour would not reverse any of the measures unveiled in George Osborne's budget.
But the shadow chancellor told BBC Radio 4's Today show that he would make economic reforms in a less "nasty way".
The Labour front bencher also reheated Ed Miliband's claim that the Tories' plans would damage the NHS and other public service.
"I don't think if we have to do that at the risk of cutting our NHS or police officers on the street or our armed forces, I think that is reckless and extreme," Balls told ITV's Good Morning Britain.
"He's trying to go further than balancing the books – he's trying to get to a surplus, and he's doing so all based on spending cuts.
"We say, why don't you put the top rate of income tax back up to 50p for people earning over £150,000? That will be a fairer way to do it.
"Sensible spending cuts, some tax rises at the top, more action on wages and tackling the abuse of zero-hours contracts. A more balanced plan which will get the deficit down but not do so at the expense of our National Health Service."
The comments come after the Chancellor announced his final budget of this Parliament to MPs in the House of Commons yesterday (18 March).
Osborne revealed that the government will raise the personal allowance for income tax to £11,000 and give tax breaks to struggling North Sea oil firms.
The announcement comes with less than 50 days to go before the general election in May, with Labour two points ahead of the Tories (36% vs 34%) in the latest YouGov poll.