Nursing unions tonight vowed to pull all their members off hospital wards and health facilities for two hours next week.
In an escalation of industrial action, a national stoppage will be held from 10am to noon on Wednesday with all midwives and nurses leaving their posts in protest to join picket lines.
The Irish Nurses Organisation (INO) and Psychiatric Nurses Association (PNA) said the move was a direct result of the Health Service Executive (HSE) threatening to cut 13.16 per cent off their salaries for participation in a work to rule.
The unions, whose 45,000 members are demanding more pay and better working hours, will continue to hold a series of two-hour work stoppages tomorrow and three-hour work stoppages on Monday, while abiding by a nationwide work to rule which came into force 39 days ago.
"It is regrettable that we have to do this," said Liam Doran, INO general secretary.
"But the provocative act of the employers has essentially meant that our members are more galvanised than ever before to see this campaign through and we believe our actions are totally driven by the approach of the employers."
Mr Doran said the unions believed the HSE's threat to cut pay from next Friday was unlawful, adding that legal action may be taken.
"We are now withdrawing all goodwill measures towards the health sector," he continued.
"And that would include involvement with such issues as the European Working Time Directive and the roll out of the Health Care Assistant Programme, seeing as we offered it as a reform, and they ignored it, we don't see why we should participate in it when they are telling us they are going to cut 13.16 per cent off salaries anyway."
Two-hour rolling work stoppages will continue tomorrow at St Vincent's Hospital and Acute Mental Health Services, Cork University Hospital and South Lee Mental Health Services, Mid-West Regional Hospital, Limerick, Sligo Mental Health Services, University College Hospital, Galway and West Galway Mental Health Services.
Thousands of nurses and midwives are also expected to join the picket lines at six locations on Monday.
The HSE also appealed directly to nurses to reflect on the current dispute.
In an open letter to nurses and midwives, HSE chief Prof Brendan Drumm reassured nurses he is willing to work with the unions to come to a resolution.
However, he also said the request for a pay increase is not within the gift of the HSE and, because of its potential knock-on effect within the wider community, needs to be considered as part of national pay agreements which we are obliged to abide by.
"To make a long term commitment of the enormity that is before us, based on the information currently available, and without a feasibility study or agreements on specific work practice changes at local level, would be the wrong course of action for patients and staff who could be affected," he added.