More than 1,100 workers at financial institution Irish Life are to walk off the job today in a row over pay.
Staff say the refusal to link wages to inflation is unfair and will leave workers unsure of future earnings.
Unite trade union members will leave Irish Life offices in Dublin and Dundalk for two hours at midday.
It is the second time they have done so and warn they will do it twice more if they do not get what they want.
Protesters are willing to enter talks at the Labour Court but Maeve Brehony of Unite says pay needs to be top of the agenda.
She said: "Irish Life proposed using an annual pay survey to determine what the market rate is and then they will pay a median of that, between 80% and 120%, which is significantly below our members' current earning potential.
"I can assure Irish Life management that, if they are willing to go to the Labour Court in respect of all of their workers, Unite will be there."