Two nursing unions in dispute with the Government have announced that they will hold a national two-hour work stoppage at all locations and involving all of their members.
The action will take place on 16 May from 10am to 12pm noon.
Nurses and midwives are also to stick to contracted hours from next week, which represents an effective overtime ban.
Des Kavanagh of the Psychiatric Nurses Association said this would eventually result in some services having to shut down.
The Irish Nurses Association & PNA have written to the Health Service Executive saying that any move by the executive to dock nurses' pay, as has been threatened, would be unlawful and that they may go to the courts to protect members' interests.
The unions have announced further three-hour work stoppages next Monday at six locations in Dublin, Sligo and Kildare which will affect Beaumont Hospital, Sligo General and Naas General and related mental health services.
The planned three-hour work stoppages at four hospitals and mental health services will go ahead tomorrow.
Following a day long special conference in Dublin today and a meeting of the unions' executives this evening, nurses said they were withdrawing all goodwill measures from the HSE.
The INO and PNA are to meet next Monday to review the campaign.
Ministers come under fire
Earlier today there were angry scenes at the Irish Nurses Organisation special conference in Dublin, during addresses by political parties on ways to resolve the 39-day-old dispute.
Some of the delegates heckled Fianna Fáil's Brian Lenihan, the Minister of State at the Department of Health and Children, after he suggested that a significant reduction in nurses' working hours could only be achieved after an assessment of the impact.
The Fine Gael leader, Enda Kenny told the conference that if he is elected Taoiseach, within a week he would personally kick-start talks on the nurses' dispute and would chair the first meeting.
Meanwhile, the Labour Party Health Spokesperson, Liz McManus told the conference that it should be possible to set down a timeframe for a 35-hour week.
The Taoiseach Bertie Ahern has said the Government would be happy to enter into an independent international assessment process to examine how the move to a 35-hour working week for nurses can be done on a cost neutral basis.
Earlier, the Minister for Health & Children, Mary Harney, told the conference that there are no winners in the nurses' dispute and that the only losers are the patients.
The minister received a frosty reception at the event, and some delegates voiced objections to her remarks during her 12-minute address to 400 nursing delegates.
In an attack on the Government and the Health Service Executive, INO President Madeline Spiers said that nurses were tired of being slapped on the back and being told they do a great job which no money could reward.
She disclosed that her annual salary was €44,000 a year.
She claimed that the HSE had entered the recent talks to try to break the two nursing unions.
Ms Spiers said the nursing profession was on the line in the dispute, and that tough decisions would have to be made today and there would be tougher weeks ahead.