More than half of NHS trust finance directors polled by the King's Fund warned that the quality of care in their area had fallen in the past year.
Almost half (48%) of CCG finance directors agreed that care had worsened in the past year.
More than two thirds of NHS trusts and nine out of 10 acute hospitals are predicting they will end the 2015/16 financial year in deficit, the King's Fund's latest quarterly monitoring report reveals.
Around two thirds of trusts are being kept afloat financially by drawing down on their reserves or through additional funding supplied by the DH, the report shows.
CCGs are in better shape financially than provider organisations, but a fifth warn they are heading for a deficit by the end of March.
The King's Fund said efforts by national NHS organisations to drive down deficits underlined 'the risk that the DH will breach parliamentary protocol by overspending its budget'.
King's Fund chief economist John Appleby said: ‘These findings are further evidence that the NHS is facing a huge financial challenge. Even with the additional funding recently provided by the Treasury and a big switch from capital to revenue spending, it is touch and go whether the DH will be able to balance its budget at the end of the year. At the same time, performance is deteriorating with key targets being missed with increasing regularity and increasing concerns being raised about the quality of patient care. This is shaping up to be a make or break year for the NHS.’
Rising NHS demand
BMA chairman Dr Mark Porter warned: 'It is clear that the government is managing the NHS into deficit by cutting resources while expecting service improvements at a time of rising demand. Asking for greater efficiency from the most efficient health service in the developed world, regardless of the mounting deficits that hobble frontline patient care, amounts to politically-driven mismanagement.
'This comes at a time when the population is growing older with complex health needs. Doctors see this as increasing and sustained strain on overstretched hospital services.? The current promised extra investment from ministers is completely inadequate to meet the problems facing a faltering health service.'
Health Minister Alistair Burt said: 'There should never be a choice between providing safe care - our top priority - and balancing the books, which is why we're investing £10bn to fund the NHS's own plan for the future, including nearly £4bn next year. Despite being busy the NHS continues to perform well - last year the service performed 1.6 million more operations and treated 2,100 more people every day within the four hour A & E target compared to 2010.'
Finance directors from 83 trusts and 61 CCGs responded to the survey.