Mr Davis said figures showed Monash Medical Centre's emergency department had used the Hospital Early Warning Status alert for 453hours in July-November 2009?. In the same period, Frankston Hospital spent 299hours on HEWS and Dandenong Hospital 253hours.

During a HEWS alert, ambulances are told the hospital's emergency department is under pressure and will accept only patients in a life-threatening condition. As a result, ambulances were "ricocheting around the suburbs like ping pong balls", Mr Davis said. "All ambulance diversions can have a direct and serious impact on desperately sick patients."

However, a Southern Health spokeswoman said patients' lives were not put at risk "and to suggest so was incorrect and alarmist". "At no point will a critically ill patient be turned away from our emergency department.

"The only role Ambulance Victoria has in response to HEWS is to consider alternate emergency departments in non-time-critical patients."

A south-east-based paramedic told the Journal that ambulance bypasses or HEWS alerts happened every second or third day and caused delays of up to an hour.

He said lives hadn't been threatened on these occasions. "If a patient is really sick, I just go to the nearest hospital. I say, 'I don't care if you're on bypass. You need to find a bed."

Cameron Lucadou-Wells