The Public Service Executive Union (PSEU) has voted strongly in favour of the new national partnership agreement Towards 2016.
Members voted by around 70 per cent to 30 per cent in favour of the deal, which gives wage rises of 10-10.5 per cent over 27 months.
The PSEU represents about 8,000 workers in the civil service and around 2,000 in public service agencies such as Fás and the Health and Safety Authority.
Deputy general secretary Tom Geraghty said the vote showed members "recognise the value of a partnership".
There has been considerable opposition to Towards 2016in both the private and the public sector. Opponents say rising inflation will effectively wipe out the pay rises and that the absence of a local bargaining clause prevents workers in highly profitable companies getting a share of the rewards.
Opponents in the public sector say the deal means that workers can only secure their increases in exchange for substantial changes in terms and conditions.
But the leadership of the State's largest public sector union, Impact, strongly endorses the deal, and the results of its membership ballot is due on Friday.
Once all unions in Congress have balloted, delegates will vote on the basis of their mandate at a special ICTU conference on September 6th.
Mr Geraghty today criticised opponents of the deal, saying they had failed to put forward any alternative.
"Time after time, the majority of trade union members show that they recognise the value of a partnership approach as they remember all too clearly that the alternative free-for-all was damaging to workers and to the economy, contributing to economic under-performance and falling standards of living," Mr Geraghty said.
The National Union of Journalists also endorsed the deal today. Only 10 per cent opposed the deal.