Paramedics said the situation peaked on Tuesday night when a crew was stuck at the emergency department for 11 hours.

Crews from Caringbah and Huskisson were called in to "plug the gaping holes in a system in meltdown", said one officer who asked not to be identified.

"We can't go on like this, the bed block was at its worst last night, the situation is critical.

"We need the minister to intervene. Enough is enough."

Health Services Union Illawarra zone delegate Howard Hughes said bringing in cars from southern Sydney and the Shoalhaven was dangerous.

"Now their services are being jammed up, we're taking cars out of those areas to respond, so that's certainly not an ideal situation," he said.

"We've had bed block here before but nothing like this. There is nothing available for the overflow and one has to question why that's the case."

Mrs Skinner yesterday said bed block at Wollongong Hospital had been greater than usual due to demand across the health system because of flu and serious illness.

She said the government had allocated $86 million to accommodate future growth in ambulatory care services, as well as a further reconfiguration and expansion of the emergency department.

The Illawarra Shoalhaven Local Health District said bed pressures at Wollongong Hospital were "currently intense", with an increased number of patients with chronic conditions requiring admission during winter.

"While the number of ambulance presentations yesterday [Tuesday] was not unusually high, difficulty in transferring patients from the emergency department to an inpatient hospital bed has caused delays," a spokeswoman said.

"The hospital is seeing an increase in the number of more acutely-ill patient presentations. There has been a 36 per cent increase in urgent triage 2 category [imminently life threatening] presentations compared with the same period last year."

The spokeswoman stressed the most serious ED presentations were treated as a priority, regardless of whether they arrived by ambulance or via the waiting room.