Some 70 jobs are to be lost in Wexford town's SuperValu supermarket when work begins on building a new store on May 1st.
In a statement, Mr Aidan Crowe, managing director of the supermarket, said they were closing for 15 months to build a new store and retail centre.
Due to the nature of the development, the existing structure would need to be knocked down and a new one built.
Before announcing the closure, the company said it had sought an alternative location but no suitable site was available in the town.
When built, the new €20 million development will include a 16,000 sq ft supermarket, an underground car-park, additional retail units and 42 apartments.
Ms Betty Dillon, the south-east divisional organiser with Mandate, the union of most of the 70 employees, said: "The workers were told the news on Monday night, and they are obviously very concerned."
She added: "Over the coming weeks we will be consulting the workers and negotiating with the company in the hope of getting the best possible redundancy package for them."