Nurses in the emergency department at St Vincent's University Hospital in Dublin have voted overwhelmingly for industrial action, due to the scale of overcrowding there.
The nurses plan to hold a lunchtime protest at the hospital next Monday, followed by a work-to-rule protest from Tuesday.
St Vincent's has said it deeply regrets the decision by nurses and that its capacity issues reflect a shortage of beds across the wider hospital system.
The hospital is one of the biggest acute facilities in the country.
The Irish Nurses and Midwives' Organisation has said that a ballot of its nurses provides for action up to and including a withdrawal of labour.
The union claims hospital figures underestimate the true level of overcrowding.
INMO Industrial Relations Officer Philip McAnenly said this morning: "Our members are totally frustrated at management's failure to address this problem or even acknowledge the extent of the crisis caused by this overcrowding.
"Patient care and safety is being compromised on a daily basis, because of this intolerable overcrowding which totally prevents our members from providing the care they believe is necessary for their patients."
Mr McAnenly continued: "Nurses took the decision to ballot following months of overcrowding, inevitably leading to increased risk to patients and intolerable conditions for nurses.
"INMO members believe they have now no option but to highlight the unacceptable conditions patients are being subjected to. The decision to commence industrial action, up to and including withdrawal of labour, seeking immediate improvements, to protect both patients and themselves, has been unanimous," he added.
Speaking on RTÉ's Morning Ireland, Mr McAnenly rejected claims that the hospital is doing all it can to ease the overcrowding issue.
He said that he believed the hospital was prioritising elective surgeries.
A spokesperson for St Vincent's said: "Management at the hospital has been undertaking a range of measures in recent months to alleviate the pressures within the Emergency Department."
The hospital "is also fully committed to working with the Emergency Department Task Force in seeking sustainable solutions to what is a long-term issue within Ireland's healthcare system”, the spokesperson added.
St Vincent's said it will be "providing additional beds under the Government's programme this winter".
It added that management will put contingency plans in place to minimise any disruption during the planned industrial action and to ensure that patients' safety is not compromised.
