SIPTU says it hopes to save as many jobs as possible at DHL Express following the company's announcement of significant redundancies yesterday.
The courier firm is seeking to lay-off 320 workers and close seven depots in Athlone, Galway, Sligo, Cavan, Enniscorthy, Waterford and Tralee.
It also plans to restructure its facilities in Dublin, Limerick and Cork.
DHL says the job cuts, which will take effect in August, are necessary because of a downturn in its domestic delivery business.
The company will meet union representatives on Monday to discuss the situation.