AMBULANCE ramping at the Hunter's hospitals became so extreme last week that at one point there were no paramedics available to respond to emergencies, the union says.
The NSW branch of the Australian Paramedics Association (APA) said ambulances were getting stuck at hospitals for "hours on end" as they waited to offload patients.
APA NSW secretary Gary Wilson said the lack of hospital resources had a "massive" impact on paramedics who were at breaking point.
"We had reports last week that there were no ambulances available - no ambulances that weren't already assigned to a case that could respond to an emergency," Mr Wilson said. "People dial Triple Zero and expect there to be someone there to help them - and that's why paramedics do this job.
"But we are extremely frustrated that we aren't being given the resources and tools to do our job."
Until Wednesday, the union says its members will refuse to collect patient information for billing. They are calling for 1500 more paramedics to be employed across NSW to bring the state in line with Queensland and Victorian ambulance numbers.
He said the latest APA survey showed three-quarters of their members were considering leaving the profession.
"I have never seen it this bad in the 20 years I've been a paramedic," Mr Wilson said. "The wheels fell off years ago. We have been dragging the car along the ground for so long now it's not funny.
"Paramedics are breaking themselves putting band-aids on a system that is in crisis."
Mr Wilson said the NSW government have the statistics, and know about the delays.
"But we're the ones that have to walk in an hour after someone has phoned an ambulance and face a family that is in crisis, worried about a loved one, and lashes out at the only people who are there - which is us," he said.
"We're tired of walking into a house and having the first words that come out of our mouths be, 'I'm so sorry it took us so long' - because the only people who can fix this are the people who hold the purse strings."