Hospital beds in England may fill up with the elderly and vulnerable because of cuts to local authority social care funding, a top NHS figure has warned.
The claim came from the head of the NHS Confederation, Nigel Edwards, in a letter to the Daily Telegraph.
Mr Edwards said people who needed medical treatment may be denied a hospital bed as a result of the cuts.
The Department for Health responded that an extra £2bn was being allocated to protect social care.
Health spending was ring-fenced in Chancellor George Osborne's Spending Review.
However, councils in England are facing a 27% cut in central government funding over the next four years.
Mr Edwards, whose organisation represents health service bodies in England, said the £2bn "interim solution to social care funding" announced in the Spending Review would be a "welcome relief to many"
Bur he said the funding squeeze could still have a "knock-on effect" on the health service.
In his letter to the Telegraph, Mr Edwards said: "Less support from council services will quickly lead to increased pressure on emergency services and hospitals.
"Hospital beds will be blocked for those who badly need care because the support services the elderly require after discharge will not be available."
He added: "When it comes to the care of the most vulnerable in our society, it really is essential that the NHS and local authorities are in it together."
The Department of Health said it understood that "social care can impact on NHS demands".
A spokeswoman said: "That's why we are strengthening programmes like re-ablement and the 30-day re-admission tariff, which will integrate hospital care with care in the community.
"We have allocated an additional £2bn by 2014-15 - this extra boost, alongside an ambitious programme of efficiency, will ensure that there is enough funding available both to protect people's access to services and deliver new approaches to improve quality and outcomes.
"We expect local health and social care professionals will work together to ensure that the funding is spent on joint health and social care priorities and improve outcomes for everyone."
Councillor David Rogers, from the Local Government Association, said the extra £2bn would not go very far.
"Of course that is very welcome, but as part of what councils said to the government before the Spending Review, there's likely to be a gap over that same time of about £6bn.
"So, there are still going to be difficulties. But I think that the important thing is to ensure that both councils and the NHS locally work increasingly closely together to provide the best service to our residents."
On Thursday, critics expressed concerns over whether the £2bn earmarked for social care, half of which is to come from a direct grant to local government, would reach its intended target.
Jennifer Dixon, chief executive of the Nuffield Trust think tank, said: "The reality is that local authority budgets will be stretched and funds for social care are not ring-fenced, so the extra £1bn per year is by no means certain."