Bosses at Leicester's hospitals have issued a new warning over growing pressure on A&E services.
They said a record number of very ill patients are being admitted and they expect numbers to rise over the next 10 weeks.
And they added that despite increasing the number of doctors, discharging more patients at weekends and opening more beds, the hospitals were full.
Earlier this week it emerged that the hospitals have had to declare an "internal major incident" seven times since the start of November to cope with hundreds of A&E patients and emergency admissions.
At a meeting of hospital directors today Richard Mitchell, chief operating officer, said: "We are more concerned than we have been at any stage in the past.
"We don't have any surge capacity, there is nothing more we can do."
When Leicester's hospitals are full it means that some patients needing to be admitted might have to wait longer until another patient can be discharged.
Some people are having to stay in hospital longer because there are no beds in community hospitals or care homes where patients needing some care could be transferred.
Mr Mitchell added: "We are stretching nursing staff very thinly."
Medical director Kevin Harris described the situation as "very uncomfortable at the moment.
"Outcomes deteriorate as a hospital becomes overcrowded."
Rachel Overfield, chief nurse at Leicester's hospitals, said there were concerns that nursing staff are so busy providing basic care that things such as infection rates will begin to rise.
She added: "This is a sign that wards are beginning to struggle and staff sickness is beginning to creep up.
"The issue is that there simply aren't the bodies to bring in."
Directors said they were surprised that to find a series of steps agreed at a crisis meeting with top health officials across Leicestershire a few days before Christmas had still not been discussed by the urgent care board, which comprises people from health organisations across Leicestershire and Rutland.
The issues raised included looking to see if extra beds can be bought in nursing and care homes and how "surge" capacity can be increased.
Non-executive director Ian Crowe said: "Inactivity across the radar of the health community is disappointing.
"We need to be more forceful to get this activity."
Karamjit Singh, who took over as chairman of Leicester's hospitals in October is now writing to the urgent care board.
He said: "I will be asking what is happening and what is not and what is proposed and I will ask for a response within 10 days."
