Paramedics have called for a royal commission into the funding, staffing and operation of South Australia's ambulance service.
The Ambulance Employees' Association says the service is in crisis and lives have been lost because of a lack of resources.
It says some calls are being left unattended, ambulances are being forced to ramp outside hospital emergency departments and low-priority patients can be made wait more than 12 hours in the face of ever-increasing demand.
"There is not a corner of the ambulance service that is not under pressure," association secretary Phil Palmer told a parliamentary hearing on Tuesday.
"It is the worst it's ever been. I've been doing this job 34 years and have never seen it this bad."
Mr Palmer said the state government had refused to increase staff numbers or provide extra ambulances to ease the problem.
He said the number of new paramedics recruited had only replaced those leaving the service, while new ambulances added had simply replaced older vehicles that were decommissioned.
The inquiry heard the worsening situation was taking an enormous toll on ambulance officers with many burnt out, stressed and suffering significant psychological problems.
"They signed up to care for the public and they do care for the public," Mr Palmer said.
"But they're having to ration that care due to the government's failure to act.
"The community is not getting the care that it needs or is paying for."
Mr Palmer called for a significant injection of funding and the appointment of more staff as fast as possible.
He said the association also believed there should be a royal commission into the service to examine funding, resources, workforce planning, commitment to public safety and the organisation's culture.
Last week its members endorsed a plan for industrial action if the government failed to respond to calls for more funding.
That could include not billing patients for ambulance transfers.
Health Minister Stephen Wade said the head of the ambulance service had previously indicated he was having fruitful discussions with the government about resources.
But Mr Wade said extra resources were not the only answer.
"We've got to have reform. We've got to make sure that we not only have ambulances but they're actually on the road at the right time.
"We've got a situation where the majority of our ambulance crews all knock off within two or three hours of one another, meaning that we've got a significant mismatch between patient demand and ambulance availability.
"We are committed to a quality ambulance service and that means reform. It's not just about more money."
Australian Associated Press