Volunteers could be asked to drive ambulances under NHS proposals to cope with staff shortages.
Health officials are also considering calling in the military in a bid to avert a crisis if pressures on services mount.
It comes amid a national shortage of paramedics, with a shortage of more than 1,000 ambulance staff in total, and attempts to recruit staff from Poland and Australia.
East of England Ambulance Services trust said it is now considering “every alternative” to maximise its resources, including the use of volunteers to drive ambulances to and from incidents.
The service, which covers Bedfordshire, Cambridgeshire, Essex, Hertfordshire, Norfolk and Suffolk, has 165 frontline vacancies, and some of the worst emergency response times in the country.
Earlier this year an MP said more than 80 deaths and 120 serious incidents had been linked to delays by the service last winter.
Cases under investigation include that of a man found dead in the street in freezing conditions 18 hours after the ambulance service was called.
The proposals, revealed in emails seen by Health Service Journal, suggest that community first responders – volunteers with five days training in first aid – should be employed to drive ambulances.
The trust said discussions were at a very early stage, and relate to the use of volunteers for “low acuity” cases, such as patients who had fallen but did not appear to have sustained injuries.
But one senior paramedic, speaking to HSJ on condition of anonymity, said it was beyond doubt that such measures would risk patient safety.
“What happens if the patient suddenly deteriorates and needs to be blue lighted to hospital?
“The paramedic in the back can’t do it. They need to be attending the patient. The staff are very against it. As a paramedic you want to be working with someone who is qualified and knows what they are doing.
“I have never heard anything like this in all my years,” he said, saying volunteers should be used in the community, not frontline ambulances.
“I told colleagues at other trusts about the plans and they were absolutely horrified,” he said.
In a statement, the trust said: “Many people who volunteer and work in patient transport services bring previous skills and knowledge that can contribute in a different way to the delivery of services during times of extreme service pressure.”
The spokesman said that if most community first responders backed the idea, there would be detailed discussions to ensure all the relevant governance, training and patient safety issues were addressed.
The trust said it was “common place” for volunteers to staff emergency ambulances in Canada, the USA and Australia.
The statement said: “While our long term plan is delivered, it is imperative that the trust consider every alternative to maximise existing and alternative resources to support our patients across the winter period.
“In doing do, the trust will consider the use of volunteers, other emergency services and the military. Indeed, the trust would rightly be criticised for not doing so.
“Despite multiple reviews in recent months, the trust’s processes have been deemed sound with no recommendations for change from any organisation.”