Siptu members have voted in favour of the second phase of Sustaining Progress by a substantial margin.
Following a nationwide membership ballot lasting six weeks, members voted by 70 per cent to 30 per cent to accept the proposed terms of the agreement.
Siptu will now cast its votes in favour of the agreement at the special ICTU conference on Wednesday.
Announcing the results, union General President, Mr Jack O'Connor said: "Union members have clearly decided in favour of the proposals on the basis of the commitments given by Government in relation to personal taxation and improved public services."
"The proposal - if agreed at Wednesday's meeting of the ICTU - is a working document with much unfinished business in the areas of take-home pay, and work related issues such as pensions, childcare and measures to support standards of employment and people's right to dignity at work."
Mr O'Connor said that the agreement would stand or fall on the basis of the commitment displayed by Government and employers.