Members of the Unite trade union in the National Ambulance Service (NAS) are to take strike action next month in a dispute over salary scales.
Yesterday, SIPTU announced strike action by its members as part of the same dispute.
The two unions have notified the HSE of a work-to-rule from 11 May, 24-hour strike action on 12 May, followed by a 48-hour stoppage on 19 May and a 72-hour stoppage on 26 May.
A National Strike Committee will decide on further rolling strike action from 1 June.
The unions have accused the HSE of failing to implement the recommendations of an independent report on updating staff salary scales to reflect changes in their responsibilities and workload.
"These are the frontline workers who save lives every day," said Unite General Secretary Sharon Graham.
"It defies belief that they have spent six years waiting for their skills and expertise to be recognised," Ms Graham said.
The dispute involves Unite and SIPTU members working in the NAS as emergency medical technicians (EMTs), paramedics, advanced paramedics, paramedic specialists and paramedic supervisors.
The HSE said it met with SIPTU and Unite in February and confirmed it was committed to entering further discussion on the substantive elements of Workplace Relations Commission proposals, which included new pay scales for relevant grades that recognise past, present and future transformative change, subject to the financial envelope approved by the Department of Health and with the consent and sanction of the Department of Public Expenditure and Reform.
"This proposal was rejected by SIPTU and Unite, who immediately advised of their intention to ballot for industrial action," the HSE said.
The HSE added that it remains committed to engagement through the dispute resolution processes set out in the Public Service Agreement.
