Nursing unions are in legal talks tonight as the deadline to halt their protests or face pay cuts looms.
The HSE has given nurses until 5.30pm tomorrow to call off their work-to-rule or face a 13 per cent pay-cut.
Union leaders are devising a strategy with lawyers tonight which they are expected to reveal at a special conference tomorrow in Dublin, due to be addressed by Health Minister Mary Harney.
"We are involved in continuing legal consultations tonight and we will be reporting back to the Special Delegate Conference tomorrow," Irish Nurses Organisation's (INO) Liam Doran said.
The INO and the Psychiatric Nurses Association (PNA) were jointly issued with a letter from the Health Service Executive (HSE) threatening the pay-cut.
The health body claimed it could no longer sustain a situation where staff are receiving full pay while on strike.
Both unions have referred the matter to their legal teams and are expected to be involved in ongoing talks in central Dublin until late tonight.
Health facilities in Blanchardstown, Galway, Naas, Cork, Cavan and Kilkenny were affected with work stoppages by nurses today, while four major hospitals are to be targeted on Friday.
Meanwhile Ms Harney and Fine Gael leader Enda Kenny clashed today over how to resolve the crisis, with the PD Minister slamming Mr Kenny's proposals to meet face-to-face with unions if elected Taoiseach.
"The INO and PNA are not looking for a meeting with the Taoiseach for tea and sympathy. It is well past that," she said.
"They [nurses] are making serious demands for substantial changes in working hours that would diminish the hours available for patient care and cost the taxpayers several hundred million euro."
She added the job of the Taoiseach was to take and hold substantive positions on serious issues.
"Responsible government is about tough decisions not just sympathetic meetings," she said.
Mr Kenny said he had visited every hospital in the country over the last 12 months and believed the health service was in a shambles.
He added if he was elected Taoiseach, he would have no problem in personally meeting the nursing unions.
On the HSE docking pay he said: "I think that is going to exacerbate the problem. This should not have been let go this far in the first place."
Labour leader Pat Rabbitte said the pay deduction threat would penalise nurses and not resolve the matter.
"I have already suggested that a timeframe should now be agreed for the phasing-in of the 35-hour week in return for necessary changes in hospital practices.
"I believe that if this were done, it could well open the way to a resolution of the nurses pay claim through existing machinery."