Tesco staff in Sligo and Ballina are set to be re-balloted on strike action next week.
Their colleagues in Letterkenny will also be balloted on possible action at the supermarket store there.
14 workers from the Sligo store joined the picket line in Longford this week as their own strike could not go ahead due to a technical error with the ballot.
MANDATE representative for the North West Ciaran Campbell confirmed to Ocean FM they will remain there until they can strike at their own store.
The row is over proposed changes to the contracts of over 250 long serving workers across the country.
Ciaran Campbell says the union expects even more support for strike action in next week’s ballots.