Some 40,000 nurses are to begin a nationwide work-to-rule from Monday week as part of their campaign for improved pay and conditions.
The escalation of the campaign will be announced later today, by the Irish Nurses' Organisation (INO) and the Psychiatric Nurses' Association (PNA), at lunchtime protests to be held in Limerick and Galway.
The unions will also announce that proposed rolling work stoppages could begin at any stage after that date.
The move comes as health service management warned that what they have termed "lightning strikes", proposed by the nursing unions could give rise to "serious ethical, legal and professional considerations" for those involved.
In a letter to the two unions earlier this week, the Health Service Employers Agency expressed concern at the provision of emergency cover in the event of work stoppages going ahead. It said that the decision of the unions not to engage meaningfully on this issue "will seriously compromise the capacity of employers to provide a safe level of care to patients".
A spokesman for the Health Service Employers Agency said it questioned whether the absence of specific notice regarding the proposed action was consistent with the provisions of the 1990 Industrial Relations Act and of the Scope of Practice Framework of An Bord Altranais .
General secretary of the INO Liam Doran last night said that all essential care would be provided for patients in the course of the dispute.
Under the planned work-to-rule there will be a ban on clerical, administrative and IT work, although nurses will continue to compile nursing notes manually. Nurses will also refuse to carry out telephone work except where this is deemed to be essential in the interest of the patient.
Nurses will also refuse to open community-based health facilities in the morning or close them in the evening. Nurses said these tasks often fell to them as they worked a longer day than other health service personnel.
