Forsa workers in the HSE will take industrial action today, over a managerial recruitment freeze.
The union says all clerical and administrative staff will be taking part in the work-to-rule action.
It's after the HSE CEO Bernard Gloster confirmed cost overruns have led to the decision to bring in a hiring freeze.
Forsa spokesperson Niall Shanahan says the action's being taken by staff right across the organisation"
"That affects grades, essentially from a Clerical Officer Grade 3 and upwards. So it's right across the administrative end of the HSE. Now, this was despite the fact that we were in talks with the HSE on a framework agreement. So Forsa it in its response to the HSE said it was unacceptable that these grades were being targeted in a renewed recruitment moratorium".