A £3.8 billion project to pull together health and social care services has been delayed because Whitehall mandarins have said the plans are not credible enough, it has emerged.
The Better Care Fund, which will draw £1.8 billion of funds from the NHS to support joined-up working between the two sectors, was supposed to have been launched last week but civil servants have questioned its viability, according to the Guardian.
Cabinet Office officials are concerned there is little or no detail about how the plans, aimed at keeping people out of hospital by providing high-quality care at home, will deliver the savings it is supposed to and have called for a "lot more work done on the policy".
A Whitehall source told the Guardian: "The Better Care Fund is based on the idea that if you invest to build up services outside of hospitals based on integrated care, that will help you to ultimately save money from the hospital budget. But the plans produced so far don't show in detail where savings will be achieved as a result of the investment, or that hospitals will be able to reduce their spending.
"Because they don't, the Cabinet Office don't think the plans produced so far are credible enough and don't have enough information in them about how the savings will be made, or detailed enough forecasts."
A report by charity the King's Fund earlier this week warned a financial crisis in the health service is ''inevitable'' and the pressure facing it has been ''exacerbated'' by the introduction of the Better Care Fund.
The shake-up, due to come into force in April next year, would channel funding into schemes that see health and social care services, usually funded by local authorities, join forces.
Ministers want it to ease pressure on hospitals and help more patients, particularly older people with long-term health issues such as diabetes, to remain in their own homes.
A Department of Health spokeswoman said: "Successive governments and health leaders have talked about joining up health and social care for decades - the Better Care Fund is a major step to making this a reality and transforming the way people are cared for closer to home.
"We have set aside time to make sure all areas have developed comprehensive plans for joined-up care. The Better Care plans start from April 2015, and we asked for early versions to be completed a year in advance so we could review them, check their level of ambition and test how they would be delivered. This is what is happening now."
A Conservative health spokesman said: " This Government is finally doing what the last government talked about but never delivered: joining up the health and social care systems."
Richard Hawkes, chief executive of the disability charity Scope, said: "Ministers have built up the Better Care Fund as the answer to the care crisis.
"We have warned that the plans won't address the issues faced by older and disabled people.
"Too many people that need support to get up, get dressed and get out of the house do not get the care they need to do the basics.
"Chronic underfunding and year-on-year rationing of care have left the system on its knees.
"Earmarking NHS cash for care was a bold move to stimulate innovative ways of working.
"But for the Better Care Fund to live up to the billing , we need to see a commitment to serious, on-going investment and a strong focus on preventing people becoming isolated and slipping into crisis.
"The Government's flagship Care Bill could make a real difference. But the reforms are at real risk.
"The Better Care Fund delay is a huge blow. But this could be compounded in a matter of weeks, if the Government goes ahead with proposed plans to further restrict who can receive care.
"Social care is set to be a real electoral issue - it's vital to millions of older and disabled people - and their carers - across the country.
"We are calling on the Government to reconsider plans to further restrict who can receive care.
"Unless care reforms are matched by the appropriate eligibility criteria - and funding to deliver it - the social care reforms will be undermined, people who need care won't get it, and the burden will be picked up by informal carers."
Shadow health secretary Andy Burnham said: "Under this Government, health policy seems to lurch from one shambles to another. This is further evidence that you can't trust the Tories with the NHS.
"After a botched £3 billion reorganisation, the NHS simply could not afford to rush ahead with these back of the envelope plans.
"This was a panicked response to Labour's plans for full integration. It was never properly thought through and was set on a dangerous and unrealistic timetable.
"This news will only deepen confusion in the NHS about Government policy. It is suffering from a real lack of leadership when it desperately needs a clear direction at a time of tight finances. David Cameron and Jeremy Hunt must urgently clarify the status of the Better Care Fund."