Frustrated NSW paramedics are taking matters into their own hands - vowing to leave non-urgent patients at hospitals so they can get back on the road to attend emergencies.

The Health Services Union says the decision is being taken to address ramping, when paramedics are stuck in hospitals supervising patients with minor ailments while needed urgently elsewhere.

The unprecedented action comes just five days before the NSW election to tackle an issue that has been festering for years amid a rise in priority one emergency calls.

HSU NSW Secretary Gerard Hayes says the stance, which begins on Tuesday, will free up paramedics to attend fresh emergency cases once they determine the condition of a patient they have brought to hospital is stable.

It will not apply to those younger than 18 or older than 85.

"It's astounding we have to do this but we have no other option," he said on Monday.

"Paramedics are at their wits' end."

Under current health protocols, paramedics are obliged to stay with patients until they are moved to a hospital bed.

The subsequent bed block prevents paramedics attending to fresh, life threatening emergencies.

"They are forced to hang around emergency departments with patients who have constipation, stubbed toes or sunburn all because there simply isn't enough staff to process a handover," Mr Hayes said.

"We are sacrificing crucial minutes where we could be responding to a potential cardiac arrest."

"At the heart of this problem is the collapse in hospital staffing."

The union says there are 12,000 vacancies across the system because people with skills and experience can't afford to live in NSW and work in health.

"This is the consequence of a decade of wage suppression," Mr Hayes said.

"We have tried every which way to propose reform options that would reduce bed block. Sadly we have hit a brick wall."