Siptu says it's unacceptable that loyal Irish workers have to witness their jobs being outsourced abroad.
170 jobs are to go at telecommunications company UPC - which is to relocate some of its operations to the Philippines.
The majority of the job losses will be in Limerick and Dublin, with a lesser number in Galway, Cork and Waterford.
SIPTU who represent many of the staff is to begin talks with the company on a voluntary redundancy scheme.
Earlier Bernie Jameson spoke to Siptu Organiser, Dennis Hynes, who said staff at UPC are heartbroken at the news.