The nurses' dispute is going back to the Labour Court, after talks between Government and unions broke down.
The talks for a new contract for nurses and midwives have been referred to the court.
The INMO has said this will allow the court "to examine the disputed clauses of the new draft contract."
The Government have also indicated that it will attend.
The INMO and Government have been deadlocked in negotiations for a new contract, which was to accompany a higher payscale, part of a proposed resolution to the nurses and midwives' strike.
The INMO has rejected draft contracts, branding them as "onerous" and "unreasonable".
Balloting by the INMO had been due to start on Monday, but its executive council have decided to postpone the start of balloting by two weeks.
They said this is in line with their previous decision that members "would not be balloted without a satisfactory contract."
The INMO's executive council will meet again on March 20th
INMO General-Secretary Phil Ní Sheaghdha said: "We are deeply disappointed with the Government's attempt to stretch the limits set by the Labour Court in these contract talks.
"Government insistence on unreasonable contract terms would put nurses and midwives in some of the most insecure jobs in Ireland, allowing unilateral changes to work locations and hours. We will not allow this.
"The Government's contract proposals are unacceptable to us and would only worsen the recruitment and retention problems.
"We believe that the Government's proposed contract goes far beyond the Labour Court recommendation and will be making this case firmly to the Court on behalf of our members."
Main image: INMO General-Secretary Phil Ni Sheaghdha attending Labour Court discussions in February | Image: Leah Farrell/RollingNews.ie