Thousands of patients could have surgeries cancelled tomorrow as up to 10,000 healthcare workers go on strike.
Ahead of the 24-hour work stoppage, there is still no sign of a resolution between the HSE and hospital support staff.
Porters, cleaners, chefs, lab assistants and maternity care assistants are among the workers that will take part in the walk-out.
The dispute has arisen over pay, with SIPTU saying the staff in question haven't received a pay rise recommended through a job evaluation scheme.
Video: Colm, a @SIPTU member in Sligo explains why 10,000 health workers are taking strike action for #payjustice this Thursday.
“We are moving with the times but our pay has stayed stagnant. The hospital won’t work without us, we want the Minister to respect us." #ourSIPTU pic.twitter.com/NV2ldM8Wv0
— SIPTU Health Division #JoinAUnion (@siptuhealth) June 17, 2019
38 hospitals and healthcare facilities will be affected by tomorrow's industrial action.
There is currently no indication of further talks taking place today.
The HSE has acknowledged the strike will have a "significant impact" on services despite back-up plans being put in place.
In a statement yesterday, the health service said: "While efforts are continuing to try to avoid industrial action, the HSE has commenced contingency planning with SIPTU at local hospital and healthcare facility level.
"This is to ensure minimum disruption to patient services, in so far as possible, and to ensure patient dignity and that essential daily care remains in place."
Patients whose appointments could be affected will be contacted by their local healthcare facility.
Opposition parties have voiced their support for the health sector staff, and have called on the Government to honour the pay agreement.
Fianna Fáil's John Brassil called on Health Minister Simon Harris to ensure efforts continue to find a resolution.
He suggested: "Fine Gael must now keep its side of the bargain or risk jeopardising further negotiations with trade union representatives."