INMO members at Our Lady of Lourdes Hospital in Drogheda will engage in a work-to-rule today.
The organisation says the action is in response to staffing shortages.
It's after the HSE confirmed 144 nursing posts in Emergency Departments across the country will be filled in the coming months.
But Tony Fitzpatrick from the INMO says that something needs to be done now as the current staffing deficits are affecting patients;