Up to 500 ambulance service personnel are to go on strike for two more days as part of a dispute over trade union representation rights and the deduction of union subscriptions at source from their pay.
The staff concerned, who are members of the National Ambulance Service Representative Association (Nasra) already staged a 10-hour work stoppage last Tuesday.
Nasra said the dates of the new work stoppages would be decided following consultation with members in the coming days.
Last week, the Government deployed Army personnel to support the HSE in the provision of ambulance services to patients during the stoppage. HSE managers who were qualified paramedics were also moved into frontline services.
Nasra is a branch of the Psychiatric Nurses Association and its general secretary Peter Hughes has argued his members are looking for the "fundamental right to be represented by a union of their choice" .
The union has called on Minister for Health Simon Harris to intervene in the dispute.
The HSE said last week the National Ambulance Service recognised the trade unions Siptu, Unite and Fórsa as representatives for its staff.
It said that in particular, Siptu was the recognised trade union for frontline personnel.
“Recognition of other associations or unions would undermine the positive engagement that exists and would impair good industrial relations in the National Ambulance Service.”