Downing Street rejects £1bn NHS Budget cut claim
The NHS budget in England could be topped up to prevent a real terms cut in health spending, government sources have indicated.
Labour claim Wednesday's Budget contained a £1bn cut in NHS funding - breaking a key coalition pledge.
But government sources told BBC News the Budget figures were "just an estimate".
The Institute for Fiscal Studies (IFS) has said the promise not to cut NHS spending may only be "barely met".
Shadow health secretary John Healey said: "The small print of the Budget confirms that David Cameron is letting the NHS down, and has broken his promise to protect the NHS.
"With the Office for Budget Responsibility's new inflation forecasts, NHS England is in fact facing a real terms cut of £1bn."
'Close to the wind'
But the prime minister's spokeswoman rejected Labour's claim - and stressed that David Cameron was sticking to the pledge he made at prime minister's questions on 15 December, when he said: "We want to see NHS spending increase by more than inflation every year."
She said the widely-respected IFS think tank had confirmed the government was meeting its pledge.
In its analysis of Chancellor George Osborne's budget, the IFS said: "In terms of the government's pledge to grow NHS spending in real terms year on year, this is now expected to be only barely met between 2010-11 and 2011-12."
It concludes: "The government is meeting its pledge, but is sailing perilously close to the wind."
The IFS said the department of health would meet its pledge because it had changed the baseline figure it used to measure its commitment.
It had been using planned spending figures for 2010/11 - but the Budget documents appeared to be using actual spending figures for the period, which are about £900m less.
Health Secretary Andrew Lansley accused Mr Healey of using the NHS as "a political football to spread scare stories that do not hold up to scrutiny".
He added: "We will increase the NHS budget in real terms every year - and the independent experts have already confirmed that this is happening."
Last year's coalition document - binding the Conservatives and Lib Dems together in a shared programme for government - pledged to protect the NHS from spending cuts.
It said: "We will guarantee that health spending increases in real terms in each year of the Parliament.
"At the last election Labour did not promise to protect spending on the NHS."