NHS trusts are expected to have seen a shortfall of as much as £750 million in the last financial year, a health chief has said.
Chris Hopson, chief executive of NHS Providers, said its estimates showed health organisations had failed to meet the £580 million deficit target set by the NHS last April.
The figures sparked accusations that the Government had staged a "cover-up" as the Department of Health last week postponed the publication of key financial data until after the election.
But the total, which was clocked up in the financial year to April, was hailed by Mr Hopson (pictured) as an improvement on previous years.
He said: "In 2015/16, because of the pressure on the NHS, the provider sector deficit ballooned to £2.45 billion. The Government made it clear that rapid reduction of this deficit was a key NHS strategic priority in 2016/17.
"Trusts agreed a detailed plan, with the full support of NHS Improvement, to reduce this deficit to £580 million and this has been largely delivered.
"This is a significant achievement reflecting a huge amount of hard work by trusts to control costs, increase productivity and improve efficiency whilst continuing to provide outstanding patient care."
The revelations come after the health service regulator said its financial information would not be released until after the June 8 poll.
NHS Improvement claimed last week it would not be publishing recent results on the advice of the Government.
Shadow health secretary Jonathan Ashworth said: "These leaked figures confirm that NHS finances under the Tories are now at their weakest and most unstable.
"Hospitals remain millions of pounds in deficit and the result is services cut back, treatments delayed and staff laid off as managers try to balance the books in the face of the Government's neglect.
"It is astonishing that it has taken a leak for this information to become public ahead of the election.
"The truth is that the Government has tried to cover up the depth of the crisis in the NHS and now we see why: seven years of underfunding have left hospital finances on the brink."
The Department of Health and NHS Improvement refused to comment on the development, citing pre-election guidelines.
NHS Providers, which counts 96% of the provider sector in its membership, based its estimates on factors including surveys of financial directors, published board papers and financial projections made in the third quarter of last year.
A spokesman said: "Given how many trusts we represent, we are very, very certain the figure will be in that £50 million range."
Copyright (c) Press Association Ltd. 2017, All Rights Reserved. Picture (c) Jeff Overs / BBC / PA Wire.