The NHS will underspend by a record £1.8bn in 2007-08, it has been reported.
That figure is more than triple the £510m surplus in 2006-07 and comes after a deficit of £547m in 2005-06.
It is partly made up of money "top-sliced" by Strategic Health Authorities (SHAs) from the budgets of Primary Care Trusts (PCTs), according to the Health Service Journal (HSJ).
Some experts have predicted that the figures could prove to be an embarrassment for the Department of Health (DH), amid accusations from the Conservatives that it is presiding over a "boom and bust" health economy.
King's Fund chief economist John Appleby told the HSJ: "An underspend by that amount will be seen as just as bad as an overspend.
"Parliament does not approve of large NHS underspends as it commits those resources for health spending, not to just sit there."
Shadow health secretary Andrew Lansley said: "The government's approach to the NHS has been one of boom and bust.
"They lost financial control and spent two years clawing back on NHS budgets.
"Top-slicing PCTs and holding large surpluses at the centre is undermining health service planning across the country and creating inefficiencies.
"These figures suggest that the NHS still lacks the kind of financial control that is necessary for greatest efficiency and effectiveness."