Politicians and campaigners have urged drastic action after mounting evidence emerged of deepening problems at Croydon University Hospital (CUH).
Councillors and an MP warned the hospital's failings placed its accident and emergency (A&E) department in jeopardy and could even topple its leadership after details of staffing shortages, depleted morale and large performance-related fines were revealed this week.
Croydon NHS Trust last month missed all but one of 16 workforce targets in areas including sickness absence, training and staff turnover, piling more pressure on beleaguered directors in the week that interim chief executive John Goulston became permanent.
It comes as a shock survey emerged showing nearly a third of the trust's staff think standards are so poor they would not want friends or family to be treated there.
Just 30 per cent of doctors, nurses and clinical workers said they would trust Croydon's health services, making it the worst ranked in the country in 2011 survey.
Croydon North MP Steve Reed described the survey results as "unacceptable".
He said: "The hospital’s senior managers and board members must get their act together quickly and put in place an action plan that will guarantee the high standards of care that people in Croydon both expect and deserve."
"If they continue to fail to do that, we will need more drastic action by bringing in a new leadership team that is capable of getting the job done."
New figures showed this week that CUH has 476 fewer workers than the 3,483 its executive board believes it needs, a shortfall of 13.7 per cent, with the highest turnover among nurses. Gaps in clinical staff are plugged by costly agency workers.
It was also revealed that the hospital has been fined £106,000 since April after ambulances were repeatedly forced to wait outside A&E to deliver patients.
It incurred a £1,000 fine each time paramedics were delayed for over an hour before being able to return to duty.
The hospital, which wants to revamp its A&E to create additional space, is likely to be hit with larger financial penalties when fines for delays over 30 minutes are introduced in April this year.
There have been 414 half-hour ambulance delays at CUH since the beginning of November, with Croydon faring far worse than neighbouring hospitals.
There have been 183 such delays at Epsom and St Helier, 143 at Lewisham and none at either Kingston or St George's.
The vice-chairman of South-West Health Overview and Scrutiny Committee warned that Croydon's poor performance could heighten the risk of it losing its A&E and maternity ward as part of the Better Services Better Value (BSBV) review.
Councillor Jason Cummings said: "The operational performance of Croydon University Hospital is now being used by other borough's councillors to suggest that it should be the A&E and maternity at CUH that should be closed, because the hospital doesn't seem to be able to operate to the standard that the public requires.
"The way BSBV is scored removes operational performance factors from the consideration, but we all know that political pressure is brought to bear and if there is a significant amount of criticism being directed at CUH it makes it harder to suggest shutting a better performing A&E department and keeping that one open."
The committee met with trust chairman Michael Bell this week and are understood to be demanding directors explain the hospital's poor performance.
Mr Cummings said: “Clearly at all levels - both operationally and in senior management - it is a very concerning picture that is coming out at the moment.
"We need to get an idea of what has happened and how they are going to stop these things happening and we need to have some confidence that they are actually in control of the situation, because everything we see at the moment suggests that they are not.
"It is one thing for them to be having fights in the boardroom, but it is another thing how it impacts on patients coming in through the door."
Geoff Martin, chair of pressure group London Health Emergency, described Croydon as "a hospital in crisis".
He said: "That is a title that could be applied to a lot of units, particularly in London, but it does seem that there is an underlying level of mismanagement of crisis at Croydon University Hospital that must be tackled before something goes seriously wrong."
Gavin Barwell, Croydon Central MP, agreed there were "real issues with the quality of care that sections of the hospital are providing" but backed Mr Bell to turn its performance around.
He said: "It is well documented there has been problems there but I hope now we can put those behind us and focus on improving the quality of service."
A spokeswoman for Croydon NHS Trust pointed out that the staff survey reflected the views of its employees in autumn 2011.
She said: "Since then we have become the first London Trust to enter the Listening into Action initiative which puts our staff at the centre of making improvements – some are ‘quick wins’ and others are more long-term improvements.
The trust said was working to drive down ambulance waiting times and close gaps in permanent staffing.
The spokeswoman said: "The data for the month of December 2012 shows a vacancy rate of just over 13 per cent.
"Although this is higher than the 11 per cent rate we expect to achieve, it is the lowest reported rate this year and the third month in a row where it has decreased."
She added: "The investment of £1.2 million in our new Acute Medical Unit will help by facilitating the flow of emergency admissions through A&E as they can be admitted to a ward which provides rapid access to diagnostic tests and treatment.
"We are also preparing a business case for capital funding to improve the layout in our A&E to provide more physical space in the department.
"In the meantime we continue to work with our colleagues at London Ambulance and neighbouring Trusts to manage the flow of patients to ensure they get access to emergency care as quickly as possible."