Minister for Public Expenditure Paschal Donohoe confirmed on Tuesday that public service employees earning under €65,000 will receive an additional €1,000 a year from April.
Mr Donohoe said this would only apply to those groups who have signed up to the Lansdowne Road Agreement, or around 250,000 people and the payment has been brought forward from September.
The measure will not apply to gardaí who are to receive about €4,000 in additional payments this year on foot of a Labour Court recommendation last November which averted a threatened strike.
The accelerated pay rise will also not apply to members of the Association of Secondary Teachers Ireland which is currently outside of the Lansdowne Road accord.
Mr Donohoe said the cost of the pay rise would be €128 million per annum, which he insisted would be found through savings and efficiencies.
The Minister denied any services would be jeopardised by the decision.
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However, trade unions said the acceleration of the payment s did not fully address “anomalies” arising from the recent pay deal with gardaí, said.
Unions were furious at the pay deal for gardaí last November as they considered the members of the force had received more money by staying outside the Lansdowne Road accord on public service pay than their members did by adhering to its terms.
It is understood that unions believe the full value of this “anomaly” to be about €1,000 per year.
The agreement announced by the Government on Tuesday only brings forward the €1,000 pay increase by five months.
Industrial peace
The new deal is contingent on industrial peace being maintained and unions continuing to abide by the terms of the Lansdowne Road agreement.
The public services committee of the Irish Congress of Trade Unions backed the deal at a meeting on Tuesday.
However, the umbrella group said it had advised the Government "that outstanding issues" would be pursued in further talks due to take place after a report by the Public Service Pay Commission is issued. The talks are expected to take place after Easter.
Spokesman for the public service committee of the Irish Congress of Trade Unions Bernard Harbour said unions perceived the acceleration of the pay rise as a "recognition that the deal done with the gardaí at the end of last year created a sense of unfairness".
“We think that that has been addressed. We think there is more to be done. But we also have the capacity to negotiate further later in the year when we sit down to talk about the successor to the current arrangement.”
“There was disappointment with what happened in November. Nobody resents gardai getting a pay rise but everybody wants to be treated equally. I think we have moved a long way now towards restoring that situation. There is more to be done but we will be able to do that in negotiations in a few months time.”
Mr Habour said that if the forthcoming negotiations later in the year on a successor to the Lansdowne Road agreement were successful, there was now the prospect of further pay increases for public service staff in 2018 which did not exist up to now.