Dunnes Stores workers who are planning a one-day strike next month have warned they may take further industrial action.
Mandate, the trade union representing almost 5,000 Dunnes Stores employees, announced that their workers will carry out an "initial one day strike" on April 2, Holy Thursday.
Gerry Light, the union's assistant general secretary, said their members working in all 107 Dunnes outlets across the country will withdraw completely from labour on that day.
"A full review will take place after the first day of the dispute and then the Dunnes Stores National Disputes Committee will decide where to go from there.
"It could be further than one day. It could be an escalation of the number of days," Mr Light said last night.
The disputes committee announced yesterday that they plan to hold strike action in three weeks time, as 67pc of their workers last week balloted in favour of industrial action over disputes in relation to pay, contracts and representation rights.
Mandate members want management at Dunnes Stores to engage with them over a number of key issues, which include the implementation of "banded hour contracts" which would give workers guarantees in terms of hours and earnings, as well as fair pay.
They are also calling for a review of the company's "excessive use" of temporary contracts of employment.
Mr Light said this is the first time the company has been hit by industrial action since 1996.
The day of strike action is likely to heavily impact on alcohol sales which are traditionally high on Holy Thursday, ahead of the ban of alcohol trading on Good Friday.
But Mr Light emphasised that the planned industrial action next month can be avoided if management at Dunnes Stores agree to "meaningful engagement".
"There is an ongoing feeling of frustration coupled with disappointment.
"This feeling of determination that we have now has set the course for the dispute and people are absolutely determined that not only is it going to happen but it is going to be a very successful dispute," he added.
The Labour Court has encouraged both parties to engage in discussion but Dunnes Stores last month issued a letter to staff stating that they would not be entering "direct discussions with a trade union".