Labour have accused Boris Johnson of lying to patients over £1bn of "new money" he pledged to the NHS.
The Prime Minister unveiled a cash pot two weeks ago boasting: "This is £1.8bn of new money. It wasn’t there 10 days ago."
But while £850m will directly fund 20 new hospital upgrades, a leaked letter says the other £1bn is set to come either from hospitals' own reserves or income - or projects that were previously approved by the government but put on hold.
The clarification emerged in a letter obtained by the Health Service Journal from Julian Kelly, chief financial officer at NHS England, to heads of NHS trusts.
It says the £1bn will mean hospital spending that was put on hold earlier this year due to spending limits can now go ahead.
Mr Kelly wrote on Sunday: "For 2019/20, the Government has agreed a £1bn increase in the Department of Health and Social Care (DHSC) baseline capital expenditure limit.
"This means that you can now revert to your original capital plans where these are funded by your trust’s own income and reserves or where DHSC has already approved the business case or funding for programmes."
A Department of Health source insisted "it is new money" and the settlement came after lengthy talks with the Treasury.
But Shadow Health Secretary Jonathan Ashworth said: "We now have it confirmed in black and white by NHS bosses that Boris Johnson was lying to patients, hardworking NHS staff and the British public.
“As we warned, this wasn’t ‘new cash’ and nor would it make up for the years of multi-billion pound Tory cuts.
"It’s been shown yet again the Tories simply don’t care about and can’t be trusted with the NHS."
Experts had previously raised questions over the "new" cash.
Sally Gainsbury, of the Nuffield Trust, said earlier this month that "to claim this as new money is a little like finally giving back the £10 you borrowed some time ago - and expecting to be applauded wildly".
She added at the time: "There’s a catch: The £1bn is cash hospitals and other NHS trusts already have but have been forbidden to spend. They earned it last yr in incentive payments for cutting their costs."
She explained that the Treasury views the money as new cash "because when an NHS Trust has a cash surplus it can’t spend, it stores it in the gov’s bank account, where the HMT effectively uses it for other gov spending."
A Department of Health and Social Care spokeswoman said: “The NHS has an extra £1.8 billion of new funding to invest in projects, money which the NHS did not previously have to spend.
“This is a brand new injection of capital that enables the NHS to get on and release urgent planned investment this year.
"This includes £850 million which will directly fund 20 new hospital upgrades – money that had not been previously allocated.
“We will consider proposals from the NHS for a multi-year capital plan in the upcoming Spending Review.”
