Nurses and midwives are to be balloted over the HSE's recruitment freeze and the impact its having on the health service.
The INMO says there are 2 thousand vacancies across the HSE - which it believes is having an effect on patient care.
The union says the HSE has left it with no other option but to ballot for industrial action.
Nurses were last on the picket in 2019 - striking over pay and staff shortages.