Staff at supermarket retailer Tesco will begin an "indefinite" strike in some 70 stores in the Republic on Thursday after talks at the Workplace Relations Commission broke down.
However the company said its 148 stores and its online services will open for business as normal on Thursday and beyond.
The dispute centres on plans by Tesco to move some 300 of its staff recruited before 1996 to less favourable contracts introduced for personnel taken on after that date.
Trade union Mandate has said issue as concern pay cuts of 15 to 35 per cent, reductions to overtime rates and changes to rosters.
While the union expects up to 6,000 workers to go on strike on Thursday, the company anticipates that just the 300 affected staff will join the industrial action.
The union, which represents some 12,000 of the supermarket’s 14,500 staff, said the proposals by Tesco Ireland management under the terms of a new contract would worsen terms and conditions for long-serving staff.
The union said the strike was "avoidable" if the retailer withdrew the threat to change employee pay and conditions without agreement. It also called on Tesco to attend the Labour Court for a hearing on the dispute.
Mandate assistant general secretary Gerry Light said it was "shameful" to tell a group of workers that their pay was being cut and then fail to give evidence to justify those cuts.
Mr Light said Mandate believed the actions of the company could set a dangerous precedent. “If the company thinks it can get away with this now, who will they target next?” he asked.
In a statement today, Tesco said it was “extremely disappointed” with the union’s strike announcement.
It said the company had tabled new porposals at the Workplace Relations Commission “that address the feedback received from our colleagues in relation to the pre-1996/97 contract changes. We are disappointed that Mandate has rejected these proposals without giving their members the opportunity to vote,” it said.
“ We have revised this offer further and we believe that colleagues should now have time to consider our new offer.”
The company said the new proposals gave staff a number of options, which included compensation for a full and partial buyout, and reopening the voluntary redundancy scheme with five weeks per of service uncapped.
“The partial buyout option means that the vast majority of colleagues will not only retain their pay rate but actually benefit from a pay increase,” it said.
“We really hope that colleagues will see this as a genuine offer that addresses the concerns raised.”
