Workers in the Wallis retail outlet on Grafton Street in Dublin are going on strike this morning.
The workers balloted for industrial action in support of their colleagues in Limerick over what they say is a dispute over redundancy payments.
Staff at Wallis in Blanchardstown have also voted in favour of going on strike next week.
"(We're) about to pronounce a dispute this morning in Grafton Street; the workers in the Wallis Blanchardstown store last night voted in support of their colleagues in Grafton Street and in Limerick," said Brendan O'Hanlon from the Mandate Union this morning.
"They too will be placing pickets next week in the Blanchardstown store," he added.