Nurses and midwives have voted against attending next week's vote by the Irish Congress of Trade Unions (Ictu) on the national pay agreement.
At a special delegates conference today, the INO agreed that representatives would boycott the Ictu vote and inform the congress that any decisions taken by Ictu on Towards 2016 will not represent their views.
The INO has an ongoing pay campaign and said it will only ballot its members on the social partnership agreement once the pay claim has been resolved. Some 250 nurses turned out for today's conference.
Ictu members are to hold a special conference at Jury's Hotel, Ballsbridge, on Tuesday, where they are expected to ratify the social partnership deal.
"Today's decision, taken after a detailed examination of all issues, reaffirms the priority that this organisation continues to give to nurses and midwives, specifically pay issues currently being considered by the Labour Court," said INO General Secretary Liam Doran.
"This is a unique, and unprecedented, decision of the INO which demonstrates the commitment of the organisation to achieve progress on its pay issues.
"The next stage in the process is to wait for the Labour Court to issue its recommendation on the eight priority claims we presented to it in June," he said.