The Irish Nurses and Midwives Organisation is to join a campaign on public sector pay which could include industrial action.
The INMO said an offer made by the Government at last month's public sector pay talks was inadequate given the current high rate of inflation.
"Our Executive have instructed that a campaign of information for members be commenced after the ICTU Public Sector Committee meet on Wednesday with a view to participate in this public service campaign up to and including industrial action if necessary," said INMO General Secretary Phil Ní Sheaghdha.
The union is accusing the Government of failing to conclude an acceptable review of the pay provisions of the 'Building Momentum' Public Service Agreement.
Earlier this month, the Irish Congress of Trade Unions announced plans for a coordinated campaign on public sector pay which may include ballots for industrial action.
In March, public sector unions and staff association triggered a review clause in 'Building Momentum' due to rising inflation.
Public sector pay talks were held at the Workplace Relations Commission (WRC) in June but ended without agreement.
The Government had offered a 2.5% pay increase this year and a further 2.5% next year but unions rejected the deal saying it 'fell far short' of inflation.
The Government has pointed out however that the 5% pay rise offered to unions comes on top of a 2% increase already provided for in the existing public sector pay deal.
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Minister says flexibility needed on both sides
The Minister for Public Expenditure and Reform has said both sides in the public pay talks will need to be flexible in order for a realistic agreement to be reached.
"Both parties have to stretch themselves, that is a reality," Michael McGrath said.
Speaking on RTÉ's Morning Ireland, he said the Government remains at the disposal of the Workplace Relations Commission.
He said that public servants deserve a pay increase, but that the Government would not chase inflation.
"We know what the lesson is from that policy, it results in inflation becoming embedded in the system and leads to second and third round effects making it even harder to get inflation under control," he said.
Minister McGrath said he believed the Government has tabled a good offer of 7% across two years and is prepared to examine what can be done for low paid workers.
"We will be as flexible as we possibly can. And there is a willingness on the part of Government to improve the offer that is there but we will need the unions to meet us as well.
"And we'll be guided by the WRC as to when they believe the conditions are right to re-enter those discussions and hopefully reach an agreement," he added.
He said the Government wants to avoid industrial action, adding he is sure the unions also want to avoid this situation.