The Irish Nurses' Organisation has denied claims by a consultant at Limerick Regional Hospital that phones calls from cancer patients were not being answered.
In a statement, the INO said the phone did not ring for a sufficient period of time to allow for any response.
It said there is no threat or attempt to jeopardise any of cancer patient's care in the Oncology Unit and a system is in place where the phones in the unit are being attended at all times.
All documentation and appropriate care is being provided for patients at this hospital.
Earlier, the Irish Cancer Society called for nurses of cancer patients to be exempted from the nurses' work to rule.
The Health Service Executive has said the level of hospital services will be unpredictable going into the Easter weekend.
Earlier, the 'Irish Patients' Association' called on the nurses to return to the bench-marking process.
Meanwhile the INO has again called on the Health Service Executive to enter talks to resolve the dispute over nurses' pay and conditions.
Speaking on RTÉ Radio's News At One, the INO General Secretary, Liam Doran, said if there is no engagement from hospital management, nurses will proceed to escalate their action by beginning a series of one-hour-long work stoppages from next Wednesday.
On the fourth day of the work-to-rule, Mr Doran rejected claims by the HSE that emergency departments are becoming overcrowded because of the nurses' action.
Mr Doran said the HSE had 'a hard neck and a short memory' to blame nurses for current congestion.
He said emergency departments had been clogged up for years and this time last year a national emergency was declared because there were so many patients on trolleys.
Speaking on RTÉ Radio's Morning Ireland, Gerry O'Dwyer, hospital networks manager with the HSE, said there had been a slowdown in outpatient departments because nurses were not using computer systems.
Congestion at A&E: HSE
He said emergency departments were also congested and asked people to attend their family doctor before coming to Accident and Emergency departments.
However Mr O'Dwyer's call was met with concern by the Irish Medical Organisation.
The chairman of the IMO's GP committee, Dr Martin Daly, said that it is unrealistic to expect GPs and GP out-of-hours services to take on the extra workload generated by the nurses' dispute.
Dr Daly also said that many serioulsy ill or injured patients will require services which are only provided by hospital A&Es, and not by GPs.
Health care facility managers are today meeting local dispute committees to make sure patient care is not compromised.
Meanwhile, the HSE has said that senior managers will be on call to provide an out-of-hours service around the country this weekend, rejecting a claim by the INO that they would not be available.
Nurses are looking for a 10.5% increase in pay and a 35-hour working week.
