By Branwen Jeffreys
BBC News, health correspondent
Many disputes centre on care for the elderly
Social care for vulnerable people is being squeezed as a result of NHS deficits, according to the Local Government Association.
The LGA says costs are being shunted to social services departments as the NHS in England aims to balance its books.
A survey of 95 councils which run social services found two thirds say NHS debts are affecting them.
The Department of Health said the NHS and local authorities had to work together for patients' benefit.
Forty per cent of the councils surveyed by the LGA said the knock on effect of the financial pressure in the NHS was worse than in previous years.
When the organisations were asked what the NHS had done in their area to affect them, half said beds had been closed, and a quarter said there had been a reduction in district nurse numbers.
Another 14% said there were increased waiting times for NHS services, such as admission to hospital while 13% said community hospitals had been closed.
In addition, more than a third of the councils in the LGA survey say they are having to take responsibility for more cases normally dealt with by the NHS.
'Grave financial pressures'
The continuing care of elderly patients is the main area where responsibilities overlap.
Almost a quarter (24%) say the local NHS is failing to fund agreed or joint services.
This might involve cuts to nursing services, meaning home helps have to take on tasks such as changing wound dressings or checking insulin levels.
Funding disputes have increased, the councils reported.
The LGA says there is deep concern on the ground about the trend towards cost-shunting and its impact on already stretched council social care services.
Sandy Bruce-Lockhart, chairman of the LGA, said councils did not want to start a war of words with the NHS.
But he added: "There are grave financial pressures on both councils and the NHS that are starting to impact on the quality of service."
However the NHS Confederation said there were two sides to the story, and some local authorities have being pushing costs the other way by tightening their criteria for looking after people.
David Stout from the confederation's primary care network said: "Pressures include increased admissions into residential care and increased workload for community based staff as well as increased pressure on out-of-hours services."
He added that the NHS and local authorities have to work together.
"Shifting the blame helps no-one - least of all the communities we serve."
Shadow health secretary Andrew Lansley said the news came at a particularly worrying time as the future of NHS continuing care and nursing support is under review
"There are severe risks that the health responsibilities of the NHS are going to be shunted into social services, with the effect either that patients go without healthcare or that they receive care but are expected to pay for it."
The Liberal Democrat spokesman for local government Tom Brake said their own research confirms cost-shunting is going on.
"Vulnerable people and their families are caused immense worry and distress when they have to use savings or sell their homes to pay for health care which should be free at the point of delivery"
Some council leaders have already met health ministers to express their concern.
The Department of Health said: "We have made it clear that the NHS must work with local government to ensure the most efficient use of all available resources in every community.
"All decisions about NHS services must take full account of the impact on social care and community based services.
"The recent local government white paper underlined the government's commitment to ensuring the NHS and councils work in partnership at a local level to secure the health and wellbeing of their community."