Members of the State's biggest union were advised yesterday to vote in favour of the national pay deal negotiated last month.
The national executive of SIPTU said the terms on offer were the best that could be achieved in a national agreement at this time.
"A return to free collective bargaining would, at best, result in winners and losers, with the lower-paid faring worst of all," it said in a statement, following a meeting in Dublin.
The deal offers most workers a 5.5 per cent pay increase, in three phases, over 18 months. Those earning €9 per hour or less are to receive an additional half per cent.
It also includes elements such as an increase on the ceiling on redundancy pay and an improvement in maternity benefit.
SIPTU members will begin balloting on the terms next week and the outcome will have a big bearing on whether the Irish Congress of Trade Unions ratifies the deal in September.
The pay terms cover the remaining 18 months of the Sustaining Progress partnership agreement negotiated early last year.