Experts from the King's Fund think tank warned that without an emergency injection of funding in the forthcoming spending review, 'a rapid and serious decline in patient care is inevitable'.
Figures from the NHS Trust Development Authority show that trusts ended the first quarter of 2015/16 £485m in deficit, more than £70m above the expected level.
Data published simultaneously by foundation trust watchdog Monitor showed that NHS foundation trusts amassed a £445m deficit over the same period - £90m over the planned level.
Monitor chief executive David Bennett said hospitals were under massive pressure and could no longer afford to continue operating as they have been.
'Trusts are working hard to provide patients with quality care,' he said. 'However, today’s figures reiterate that the sector is under massive pressure and must change to counter it. The NHS simply can no longer afford operationally and financially to operate in the way it has been and must act now to deliver the substantial efficiency gains required to ensure patients get the services they need.'
Unite national officer for health, Barrie Brown said: 'The financial chickens are coming home to roost big-time. This is what happens when you have growing demand for NHS services and then decide to impose £20bn of so-called "efficiency savings".
'Health secretary Jeremy Hunt needs to start banging the cabinet table to get more funds in real terms from the chancellor George Osborne, otherwise the NHS will go into a financial meltdown.'
King's Fund policy director Richard Murray said NHS providers were heading for an unprecedented end of year deficit.
‘Warnings of a deficit of at least £2bn by the end of the year are well-founded. It is inconceivable that an overspend of this magnitude can be covered by the end of the year,' he said.
‘Overspending on this scale cannot be attributed to mismanagement or waste among individual trusts. It reflects the impossible task of delivering high quality care for patients with inadequate funding.'