NHS bosses are keeping cost-cutting plans that could lead to hospital and A&E closures secret from the communities they will affect, an investigation has found.

Health managers in 44 areas of England have been ordered to draw up strategies setting out how they will reduce costs, change services and improve care in the wake of a record £2.45 billion deficit.

But they have been told not to reveal the plans to the public or the media until they are finalised and have been approved by their own officials first.

A report from leading think tank the King’s Fund warned that patients and the public were “largely absent” from the development of the plans, which could see sweeping closures of health services affecting millions of people.

“All the national guidance says don’t share it, don’t put in the public [domain]," said one local health leader interviewed by the King’s Fund.

The government wants to “manage the national political messages to make sure that things like hospital closures and things like that don’t get leaked,” they said.

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The ‘sustainability and transformation plans’ (STPs) could see some hospitals, A&E units or maternity units close, and other services merged.

NHS England has told local managers to refuse applications from the media or the public wanting to see the proposals under the Freedom of Information Act, according to the report.

The King's Fund said NHS England had set very tight timescales, which are partly to blame for why patients and doctors have been shut out.

“Leaders told us it was almost impossible to involve patients and the public effectively in the plans within the timescales available,” the report said. “As one leader told us, ‘it’s a complete no-hoper’.”

However, some of the plans have been published or leaked by those who disagree with the lack of public involvement.

Some councils have objected so strongly to the secrecy they have ignored NHS England's demand to keep the documents private until a later stage and have published them on their websites.

Earlier this month it was revealed that a number of Merseyside hospitals could be merged, A&E departments downgraded and Liverpool Women’s hospital relocated in an attempt to plug a £900m finance gap in the area.

In north west London, there are plans to reduce the number of sites offering a full range of services while Birmingham and Solihull's STP proposes a single “lead provider” for maternity care.

In pictures: Junior doctors first all-out strike Show all 10 1 /10 In pictures: Junior doctors first all-out strike In pictures: Junior doctors first all-out strike Doctor in acute medicine, Melissa Haskins, holds up a 'I ain't afraid of no Hunt' sign whilst striking with other junior doctors outside her hospital, St Thomas' Hospital in London Getty Images In pictures: Junior doctors first all-out strike Accident and emergency junior doctor, Jennifer Hulse, holds a homemade placard outside St Thomas' Hospital as she strikes with colleagues in London Getty Images In pictures: Junior doctors first all-out strike Demonstrators and Junior doctors hold placards as they protest outside the Basingstoke and North Hampshire Hospital, in Basingstoke during a strike by junior doctors Getty Images In pictures: Junior doctors first all-out strike Demonstrators and Junior doctors hold placards as they protest outside the Basingstoke and North Hampshire Hospital, in Basingstoke during a strike by junior doctors Getty Images In pictures: Junior doctors first all-out strike A supporter displays a slogan on her bag during a junior doctors' strike outside St Thomas' Hospital in London Reuters In pictures: Junior doctors first all-out strike The picket line outside King's College Hospital in London PA In pictures: Junior doctors first all-out strike The picket line outside King's College Hospital in London, as thousands of junior doctors begun the first all-out strike in the history of the NHS after the Health Secretary said the Government would not be "blackmailed" into dropping its manifesto pledge for a seven-day health service PA In pictures: Junior doctors first all-out strike Junior doctors and supporters take part in a strike outside the Royal United Hospital in Bath Getty Images In pictures: Junior doctors first all-out strike Doctor in acute medicine, Melissa Haskins, holds up a 'I ain't afraid of no Hunt' sign whilst striking with other junior doctors outside her hospital, St Thomas' Hospital in London Getty Images In pictures: Junior doctors first all-out strike Dave Prentis, UNISON general secretary visits a British Medical Association picket line at Royal Sussex County Hospital in Brighton, to show support for striking junior doctors on the second day of the union's annual health conference PA

Some councils have objected so strongly to the secrecy they have ignored NHS England's demand to keep the documents private until a later stage and have published them on their websites.

NHS England and some health experts say the changes will improve patient care and are necessary to fulfil Health Secretary Jeremy Hunt's plan for full seven-day services, but campaigners argue they are just a way of cutting services.

Chris Ham, chief executive of the King's Fund, said it was a “heroic assumption” to say out-of-hospital services and GPs could take on more of the work currently done by hospitals, given how under pressure they were.

He criticised the lack of back-up plans to the proposals, but said STPs still offered the “best hope” of improving health and care services.

“The introduction of STPs has been beset by problems and has been frustrating for many of those involved, but it is vital that we stick with them,” he said.