Ambulance services in the Midlands face curtailment from Monday because of a dispute involving crews.
Emergency medical technicians (EMTs) from five centres in the region are to withdraw on-call cover following the breakdown of talks at the Labour Relations Commission. The stations to be affected by the dispute are Portlaoise, Tullamore, Athlone, Longford and Mullingar.
EMTs provide back-up to on-duty ambulance crews, answering 999 calls if the duty ambulance is busy.
SIPTU claims patients would be better served if the on-call system was withdrawn and replaced by a second on-duty ambulance at each station.
"Such a move would improve response times in the midlands by up to 15 minutes in some cases," said the union's Mullingar branch secretary, Mr Séamus McNamee.
"In addition to improved patient care, the abolition of the on-call arrangement would improve the quality of life of EMTs who, in many cases, stay at their ambulance station for up to 30 hours at a time in order to operate the on-call shifts between on-duty shifts," he added.
Several reports had recommended the abolition of the current system.
In November last year EMTs had sought the replacement of the existing on-call arrangements with an on-duty system. "No action was taken on these proposals," Mr McNamee said.