Parts of the NHS "will implode" this winter, an expert has warned, as new figures show falling A&E performance over the past few months.
Dr Mark Holland, president of the Society for Acute Medicine, said the days when summer used to provide a respite for busy emergency departments have now gone, and instead the NHS faces an "eternal winter".
The NHS was now "on its knees" and a major increase in hospital admissions due to flu or the sickness bug norovirus could lead to collapse, he added.
Dr Holland spoke out as new figures show that waiting times in A&E units this summer have been worse than for most winters for over a decade.
One in 10 patients waited for more than four hours in A&E during June, July and August - worse than any winter for the last 12 years bar one, analysis by the BBC showed.
Only last winter marked a worse performance since the target was launched in 2004.
Data from NHS England for the summer also showed hospitals are missing key targets for cancer, routine operations and ambulance response times.
Delayed discharges - where patients are struck in hospital despite being medically fit to leave - continued to rise, with a record high during August.
The Local Government Association (LGA) has said a funding gap of at least £2.6 billion is opening up for providing social care in the community. This effects discharges because care packages are not always in place for those leaving hospital.
Dr Holland said: "The NHS is on its knees and, this winter, areas will implode around the country. There is no reserve left.
"We coined the phrase eternal winter months ago in relation to increasingly poor performance and this data is clear evidence that is what we are now dealing with.
"Over the coming weeks and months, if we see a major increase in admissions due to flu or bed closures due to norovirus, we will collapse.
"The Government has failed to acknowledge or address the scale of the crisis in social care and delayed discharges and, at present, I see no plan of action in place to prevent it derailing the health service.
"If we are unable to discharge patients and release pressure on our emergency departments and acute medical units at the front door, the system grinds to a halt."
Nuffield Trust chief executive, Nigel Edwards, said only "a small handful of hospitals" now hit the A&E target.
"We need to look at the underlying causes," he added. "Our analysis of hospitals suggests that after years of squeezed bed numbers, there is not enough space left to move patients through at the rate we want. The practice of counting bed use at midnight misses the real crunch points during the day.
"On the front line, leaders should work on better monitoring and control of patient flow minute by minute. Helping the longest staying patients to leave hospital sooner should be a priority, although it will be difficult with the social care system on its knees. Nationally, we should be realistic about what hospitals can do when they are this full, and how hard it will be to free up space again."
Shadow health secretary, Jonathan Ashworth, said: "'The figures expose the Tories' record of failure on the NHS.
"On Jeremy Hunt's watch hospitals are now bursting at the seams with thousands of people waiting hours in overcrowded A&E departments and on hospital trolleys.
"These pressures are a direct consequence of the decisions Jeremy Hunt has taken. This Government's cuts to social care over the last six years have left councils struggling to provide basic support for older people in the community and the growing crisis in general practice is forcing many people to travel to A&E because they can't get an appointment with their family doctor."
Matthew Swindells, NHS England's national director for operations and information, said: "While hospitals are continuing to look after more than nine out of 10 A&E patients within four hours, and A&E performance improved this month, today's CQC report highlights the impact of rising social care pressures on emergency admissions and delays in people leaving hospital.
"As the CQC argues, if we are to solve these pressures, the transformation work kicking off this autumn led by local health and care organisations, is essential."