SIPTU is meeting workers from Glanbia's Edenderry plant this morning to discuss the immediate future of their jobs.
Around 280 employees are facing an uncertain future after the Co Offaly factory was badly damaged by a fire over the weekend.
Glanbia plans to redeploy 220 staff at its other plants in Roscrea, Parkmore and Carrig, 60 of them on a full-time basis and 160 on a weekend rota system
However, it is not yet known how the other 60 staff will be affected.
SIPTU says it wants a commitment from Glanbia that the Edenderry factory will be rebuilt, but the company has yet to make such a promise.