Members of the State's biggest public sector union have voted overwhelmingly in favour of the new national pay deal.
IMPACT will now support ratification of the deal at a special delegate conference of the Irish Congress of Trade Unions (ICTU) next month.
Its members voted by a majority of just over nine-to-one to support the deal, agreed in June in negotiations between employers, unions and the Government.
It offers most workers a pay increase, in three phases, of 5.5 per cent over the remaining 18 months of the Sustaining Progress partnership programme. Those earning €351 or less per week, or a maximum of €9 per per hour, are to receive an additional half per cent.
IMPACT general secretary Mr Peter McLoone said Sustaining Progress was delivering the highest pay increases of any of the world's leading economies.
Workers would receive cumulative pay increases of 13.16 per cent over the three years of the programme, he said. In addition, public servants would receive benchmarking payments worth an average of 8.9 per cent.
He said in exchange for the basic increases, Irish workers were delivering the highest productivity improvements in Europe, and the EU's highest rates of economic growth.
"And Irish public servants are delivering independently-verified service improvements in exchange for benchmarking.
"It's a testament to social partnership, and positive proof of the benefits workers gain from union membership," said Mr McLoone, who is also vice-president of the ICTU.
IMPACT has 52,000 members, and will cast nearly 10 per cent of the votes at the ICTU conference on September 1st. All of its delegates will be mandated to vote in favour of the deal.