Tesco Ireland have said that all their stores will remain open today despite what they called an "unjustified strike" by members of the trade union Mandate at eight stores.
It comes despite Mandate last night calling on the retailer to enter talks.
The workers are going on an indefinite strike in a row over contracts for some long-standing staff, with more to follow.
Tesco, which is calling on workers to accept a Labour Court recommendation, said it is focused on continuing to serve its customers "despite this unnecessary action by Mandate".
The union's Assistant General Secretary Gerry Light last night said the strike could be called off "if Tesco Ireland agrees to operate on the basis of making changes to workers’ contracts through agreement".
"However, despite Tesco’s highhanded behaviour our offer to sort out the issues in this dispute still stands. Let’s get into talks and resolve the issues involved," he added.
Tesco said they "remain shocked" that Mandate is still going ahead with this strike and that "the union has advised customers to shop in non-unionised competitor stores".
Tesco said: "Five stores have voted against strike action, two stores called off their strike today due to serious concerns about the conduct of their ballot and one store decided not to proceed with its ballot before it commenced.
"Despite the actions of Mandate, the company has not made any changes to the pre-1996 terms and conditions of the 250 workers at the centre of the dispute. Tesco is prepared to abide by the Labour Court Recommendation in relation to this small number out of our 14,500-strong workforce and is calling on Mandate to do the same. We have always sought to do this by agreement and have spent 13 months in discussions with Mandate.
"Therefore it is unusual and most abnormal that Mandate is refusing to accept the Labour Court’s Recommendation in this dispute on flexibility."