The private sector will make £23bn in profits and interest over the next 30 years by building NHS hospitals, campaigners have calculated.
The NHS pays the building contractor over a 30-year period
Under the private finance initiative, a company builds a hospital and then gets "rent" from the NHS for a set term.
A report by the Keep Our NHS Public claims the government is carrying out "patchwork privatisation" of the NHS.
The Department of Health said it "did not recognise the figures" and was "committed to a publicly funded NHS".
The report was being launched at a conference for health campaigners in London on Saturday.
It says: "Unlike the Thatcher privatisations of the 1980s, the whole NHS is not being put up for auction.
"Instead, it is being parcelled up into bite-sized pieces and handed over to private control bit by bit.
"This is happening on such a scale and at such pace as to make it a unique phenomenon."
Alex Nunns, of Keep Our NHS Public, said: "Unbeknown to the public, the NHS is paying astronomical sums of money to the private sector.
"When the NHS is making cuts and closures across the country, it's time to ask if this is the best use of public money."
As recently as October, the government disclosed some of the figures involved in the NHS's use of PFI schemes to finance new hospitals.
The figures, which emerged in a response to a Parliamentary Question tabled by Shadow Health Secretary Andrew Lansley, showed that the NHS would pay a total of £53bn to the private firms involved.
That amount was the total cost, as opposed to the numbers in the report by Keep Our NHS Public, which relate to profits.
But the Tories claimed at the time that the new hospitals themselves were only worth £8bn, leaving "completely unjustifiable" extra costs of £45bn.
A spokesman from the Department of Health said in response to the new report that the annual payments made by NHS trusts to private sector partners covered financing charges, repayment of capital, building maintenance and, in most cases, all the non-clinical support services like cleaning and catering.
He said the last two of this list could account for between 40% and 50% of the annual payments.
"The NHS has always used the independent sector for treating patients," he said
"But the difference is now that we pay much less for this extra capacity for NHS patients thanks to our robust contracting."
He said more than 250,000 people had received treatment faster than they would otherwise have done thanks to the independent sector.