The upcoming Budget will not include detailed spending allocations for Whitehall departments for the years ahead, chancellor Alistair Darling said today.

Mr Darling confirmed that he plans to protect funding for the NHS and schools, but said he would not conduct a full spending review until there was more certainty about the direction of the economy.

He insisted Labour was “absolutely committed” to halving Britain’s record deficit within four years, and repeated warnings that to go faster and further - as Conservatives plan - would be an “unacceptable risk” to the economy.

No date has yet been set for the last Budget before this year’s general election, leading to speculation that prime minister Gordon Brown may be planning to go to the country without a final statement from his chancellor that might expose the full extent of the UK’s economic difficulties to voters.

Conventionally, around four weeks’ notice is given of the Budget date, leaving very little time for it to be announced ahead of the favoured election date of 6 May.

Speaking to BBC1’s The Politics Show today, Mr Darling gave no hints about the timing of his statement.

But he made clear: “I am not going to do a spending review now. What I have said is I wanted to protect the NHS and I also wanted to protect the schools budget, because both of these are absolutely crucial in terms of fairness and to our future.

“But I am not going to do a detailed spending review.”