The number of patients forced to wait for more than four hours in accident and emergency departments before being treated has reached its highest level in a decade, a new report suggests.
In the last three months of 2012, some 232,000 patients waited for more than four hours in A&E - waiting 38 per cent over longer than they had in the previous three months of the year.
Research by health think tank The King's Fund shows that between October and December the proportion of patients waiting more than four hours was at its highest level since 2003.
The King's Fund said that as financial pressures continued to "bite hard" on the health service there was growing pressure on emergency care.
So-called "trolley waits" - where patients who attend A&E and need to be admitted to hospital have to wait before they are given a bed - were also at their highest rate since the same period in 2003.
We need to look beyond short-term solutions that balance the books. Mike Farrar, NHS Confederation chief executive
"The NHS faces unprecedented financial pressures, and there are growing worries that patient care will suffer," Professor John Appleby, chief economist at The King's Fund said.
"For social care, it will be increasingly difficult for councils to make further savings without directly cutting services or affecting quality.
"Health and care services have coped well until now, but it is clear that many organisations expect things to become much more difficult over the coming year."
The Department for Heatlh said the NHS is on track to deliver up to £5bn of savings by the end of 2012/13 and has made a strong commitment to adult social care with plans to invest an extra £7.2bn over four years.
It also pointed out that it was The King's Fund which supported its view that £7.2bn was enough for councils to maintain services, provided they focuses on efficiency.
Health Minister Lord Howe said: "Patients need to be able to rely on prompt, high quality, urgent and emergency care and treatment. We are clear that patients shouldn't face excessive waits for treatment."
The report however suggests that health and social care providers are "pessimistic" about the financial outlook of their organisations and some are concerned that the quality of patient care has suffered as a result.
Two-thirds of the 48 NHS finance directors and 58 directors of adult social care services which were surveyed said they were concerned about the financial outlook across the local health and social care system in 2013.
The NHS has been tasked with making £20bn of efficiency savings by 2015, while social care providers are struggling with tight budgets and growing numbers of people who need care.
A third of NHS finance directors said the quality of NHS care in their area had deteriorated over the past 12 months.
What's more half of social care directors said they thought the quality of services they commissioned had worsened in the past year, with a third fearing they would have to reduce services over the coming year.
Mike Farrar, NHS Confederation chief executive, said: "Despite huge efforts to maintain standards of care and finances, NHS leaders are increasingly concerned about the pressures mounting on their organisations and the knock-on impact of reductions in funding for local government services.
"The findings of the Francis inquiry reinforce the fact that we must keep the focus on patients first and foremost.
"We need to look beyond short-term solutions that balance the books and examine how we can transform the way we deliver care so that it provides the best outcomes for people, in a way that is fully sustainable in the long term."