Ambulance crews should be given body armour to protect them in dangerous situations, union leaders say.
Ambulance crews are more likely to be attacked than hospital staff
The Association of Professional Ambulance Personnel will use a conference next month to call for the £300 anti-stab vests to be provided.
The union said paramedics and technicians needed the vests as they were twice as likely to be attacked as hospital staff.
But ambulance chiefs said measures such as safety training may be better.
The union has been campaigning for the vests since 1997, but is renewing its calls arguing that the forthcoming relaxation in the licensing laws could place ambulance staff in even more danger.
There are more than 110,000 attacks against NHS staff in the UK each year - although proportionally more are committed against ambulance crews than other doctors and nurses.
Only two of the UK's 34 trusts - London and Essex - routinely use the vests, the union said.
London introduced them in 2002 - a year after a paramedic was stabbed at a call out in the east of the city.
Mark Weatherhead, the association's general secretary, said many ambulance bosses had been reluctant to provide them for front-line staff.
"It is a sad reflection on the violent nature of our society today that we are having to discus the concept of body armour in our profession."
He added: "At a time of escalating hostility toward 999 crews, the impending relaxation of the licensing laws in November is only likely to make the situation worse."
He said the issue would be discussed at the association's annual conference in the West Midlands in November.
But Richard Diment, chief executive of the Ambulance Service Association, which represents ambulance trusts, said: "We do not oppose the use of body armour in principle, but it may be that trusts believe training to help ambulance crews handle dangerous situations is better.
"And of course, we have a duty to consider the safety of our employees."