But nurses who remain at their stations providing emergency cover during the stoppages will be paid, according to Brendan Mulligan, assistant chief executive of the HSE employers agency.

The Irish Nurses Organisation and the Psychiatric Nurses Association, which represents the 40,000 nurses engaged in a nationwide work-to-rule in support of their claim for a 35-hour week and a 10.6% pay rise, will inform management tomorrow of the hospitals which will be subject to work stoppages.

Liam Doran, general secretary of the INO, confirmed to the Sunday Tribune that three major acute hospitals, including one in Dublin, will be targeted on Wednesday.

Doran said that the stoppages will most likely be one or two hours and not four hours as previously suggested. But he threatened that the rolling stoppages will move on to another set of hospitals after Wednesday until the dispute is resolved.

The unions have also agreed emergency cover provisions with all hospital managers to be provided with an agreed number of nurses staying at their posts during any stoppages.

"This will mean that all nurses in ICU and coronary care units, for example, will stay at their posts during a stoppage.

Staffing levels will not drop below night duty level, " Doran promised. "But elective areas, out-patients and day care will be affected" he warned, adding that the government now has a "three day window" to resume talks with the nurses.

On public support, Doran said that the nurses are "holding their own". As regards opposition and backbench support, he said it was never likely that the nurses "would get overt support from such quarters".

"But we will see what will happen as we get closer to polling day particularly around the fifth seat in marginal constituencies."

Health minister Mary Harney and Taoiseach Bertie Ahern have so far held firm, believing that to concede would spark an avalanche of claims across the public sector and collapse the partnership process.

While there was no sign of any breakthrough, Brendan Mulligan said this weekend that the sides were "not that far apart" on the 35-hour week and the only issue outstanding is a timetable for its introduction once a risk assessment has been done.

"But on pay, the government's public service pay policy applies" said Mulligan.