The NHS needs much more than the £8bn ministers have promised and will not deliver the £22bn of savings it has pledged, according to NHS finance chiefs.

The service in England is heading for a deficit this year even bigger than the £2bn already widely forecast, according to research by the Healthcare Financial Management Association (HFMA).

Finances have deteriorated so sharply recently that all of England’s 156 acute hospital trusts are set to end 2015-16 in the red, the first time that has happened, the HFMA predicts.

It urges the government to give the service more than the planned £8bn or accept that failure to do so will lead to unpopular measures such even greater rationing of patients’ access to treatment or the introduction of charges.

The findings of an HFMA survey of more than 200 finance directors of NHS bodies including hospitals comes a week before the chancellor, George Osborne, is expected to set out how much extra funding the NHS will get in the next few years in his spending review on 25 November.

NHS managers are keen to see the £8bn “frontloaded”, with as much of it as possible announced next week and provided from next April in order to pay for building up new services outside hospitals.

“With just days left before the spending review, finance directors are telling us they’re not confident in the current plans and need more clarity. While they’re not convinced the promised £8bn in funding is sufficient to address the whole financial problem, it’s clear they need it sooner rather than later,” said Paul Briddock, the HFMA’s director of policy.

The survey found that 84% of finance directors believe they cannot deliver the Five Year Forward View, the NHS’s ambitious blueprint for securing its future, without extra money. And 88% believe they cannot realise the 2-3% annual improvements in productivity envisaged in the plan which are crucial to realising the £22bn of “efficiency savings” by 2020 that the NHS England chief executive, Simon Stevens, has promised.

Their deep pessimism about the deal Stevens has made with ministers to secure the service’s future – unprecedented improvements in efficiency in return for a major cash boost – shows they believe that the blueprint is unlikely to succeed because it is based on hopelessly unrealistic financial assumptions.

Overall, 46% of respondents were not confident that, and 53% did not know if, the NHS could make the £5bn a year of savings recently identified by Lord Carter of Coles. More than half (57%) doubt that the Vanguard areas hailed by Stevens as crucibles of a future NHS will save enough money to bridge the gap between the £22bn target and Carter’s £5bn envisaged savings.

In addition, 43% said the NHS could not keep providing the current quality of service unless the £8bn was increased while 56% said maintaining quality of care depended on the £8bn being heavily frontloaded. They blame the cost of agency staff and bedblocking caused by inadequate social care for hospitals’ fast-ballooning overspends.

But the Department of Health insisted that it still expected the NHS to find the £22bn of savings and get by with the extra £8bn.

“We are committed to the values of the NHS which is why we have invested £10bn to fund the NHS’s own plan for the future and spending as a proportion of government spend has increased in every year since 2010,” a spokesman said.

“While the NHS is busy, the cost-controlling measures we have introduced like clamping down on rip-off staffing agencies and expensive management consultants will help to support finance directors and the NHS to ensure every penny is spent on patient care.”

Meanwhile, the Cavendish Square Group, which represents London’s 10 mental health trusts, says it is “seriously concerned” that GP-led clinical commissioning groups in the capital “will again raid mental health budgets to fill the ever growing deficits in the acute hospital sector”.

Although mental ill-health accounts for about 25% of the entire burden of illness, it receives only about 12%-13% of the NHS budget and that proportion is falling.

The amount London CCGs spend on mental health fell over the past year from 12% to 11%, the group adds. “It is as if all the promises of more spending on mental health count for nothing. It cannot be right that we run the NHS on the basis of robbing Peter to pay Paul and it simply cannot go on.”