SIPTU members have voted by a large majority in favour of the new social partnership agreement.
The union said today that 72% of its members have voted to accept the Towards 2016 deal in a ballot over the past few weeks.
The agreement includes pay rises totalling 10% over 27 months.
SIPTU's support is a major step towards getting the document ratified at a special ICTU conference next month as it is Ireland's largest trade union, with 200,000 members.