Nurses say conditions in the NHS are the worst they have experienced, the Royal College of Nursing has said.
In a separate move, 50 leading doctors have warned the prime minster in a letter that lives are being put at risk due to mounting pressures on the NHS.
Charities working with elderly people said long-term solutions were needed, with a similar call from a group of Conservative, Labour and Lib Dem MPs.
Health officials said they were investing more in care.
The fresh calls for government action come a day after documents leaked to the BBC showed record numbers of patients are facing long waits in A&Es in England.
The document compiled by regulator NHS Improvement shows this winter is proving to be the most difficult for more than a decade, with nearly a quarter of patients waiting longer than four hours in A&E last week.
Janet Davies, chief executive at the Royal College of Nursing (RCN), said she had heard from frontline nurses who wanted to give the best care they could to their patients but were told to discharge them before they were fit just to free up beds.
One sister in charge of a major treatment centre in accident and emergency, told the RCN: “At one point our treatment area, meant for 20 patients, had 56 patients crowded in corridors and around the nursing station.
“Our resuscitation room built for six regularly had seven.”
The college said nurses from Scotland to London had reported serious concerns about the quality of care they were able to provide.
Meanwhile a letter from the Royal College of Physicians (RCP), called for urgent investment to help “over-full hospitals with too few qualified staff”.
‘Lives at risk’
Speaking to the BBC, Prof Jane Dacre, president of the RCP, said: “Our members tell me it is the worst it has ever been in terms of patients coming in during a 24-hour period and numbers of patients coming in when there are no beds to put them in.
“And there are patients within the hospital who can no longer get home because of the difficulties there are in placing people in social care.”
She added: “Our members fear that patients’ lives are at risk because they can’t get round to see patients who aren’t in the emergency and accident department or are waiting for results to come back.”
And the Royal College of Radiologists has backed the RCP in its own letter to the PM, calling for more investment and urging the government to take “immediate and longer-term measures to address the issues”.
And in a separate letter to the prime minister, 75 charities and individuals working in health and social care said there must be a long-term, cross-party solution to what they called “the crisis in funding”.
Led by the charity Independent Age, they said: “Unless you adopt a bolder approach, millions of older, ill and disabled people and their carers, will continue to be badly let down.”
It comes as a cross-party group of more than 20 MPs, led by MP Norman Lamb, launched a campaign urging the government to establish an NHS and care convention to find a long-term solution to funding issues.
A government spokesman said: “We recognise the pressures of an ageing population which is why we recently announced almost 900m of additional funding for adult social care over the next two years.
“But as the prime minister has made clear, this is not solely about money. That is why we are working to find a long-term, sustainable solution which helps local authorities learn from each other to raise standards across the whole system.”
A Department of Health spokesman added: “Since just last year, we have 3,100 more nurses and 1,600 more doctors. We’re also joining up health and social care for the first time and investing 10bn to fund the NHS’s own plan to transform services and relieve pressure on hospitals.”
Separately a National Audit Office report raised concerns about proposals to increase access to GPs at weekends and evenings.
The spending watchdog said the government had not evaluated the cost-effectiveness of the plans.
Read more: http://www.bbc.co.uk/news/health-38570177