The Irish Nurses and Midwives Organisation is meeting to decide whether to ballot for strike action after members overwhelmingly rejected Government pay proposals aimed at addressing staff shortages in the health service.
However no formal announcement is expected until tomorrow when the two-day meeting concludes.
Meanwhile, the Health Service Executive has invited the INMO to talks on Thursday in a bid to resolve the dispute.
In a briefing to the INMO membership, General Secretary Phil Ní Sheaghdha noted that members had overwhelmingly rejected the Public Service Pay Commission proposals on 17 October.
Despite the union seeking an urgent meeting with health employers to discuss the situation, it took the management side until Friday to issue an invitation to talks on 8 November - after the union's leadership was due to meet.
Ms Ní Sheaghdha described the lack of urgency and level of complacency in addressing chronic understaffing in the health service as "unacceptable" and "disappointing".
She added that the INMO Executive will factor that into its consideration of steps required to address the serious shortage of nurses and midwives in the public health service.
She also informed members that on Friday 26 October, the union was invited to attend the Oversight Body of the Public Service Stability Agreement (PSSA), which oversees compliance with the current pay deal for State employees.
However, the union declined that invitation describing it as premature - as the union is not currently in dispute with the HSE, and no meeting with the HSE or the Department of Health had yet taken place.
The PSPC proposals rejected by the INMO (and separately by the Psychiatric Nurses Association) would have seen a package of allowances totalling €20m per year targeted at areas with the worst staff shortages, though the allowances would only have benefited around half the union's 40,000 members.
However, the nursing unions have consistently argued that only a 12% across the board pay rise will make nursing sufficiently attractive to address staffing difficulties.
In a letter to HSE National Director of HR Rosarii Mannion last Friday, the INMO said its executive would consider "positively" the invitation to Thursday's talks.
However, Ms Ní Sheaghdha insisted that no other union representing nurses (the PNA and SIPTU) should participate in the meeting, though she said the HSE was free to have separate engagement with those groups.
Around 4,000 nurses represented by SIPTU accepted the PSPC pay proposals.
SIPTU's Health Division Organiser Paul Bell said his union would expect to be invited to Thursday's talks with the INMO, given that his union represents 4,000 nurses.
The HSE has invited the Psychiatric Nurses Association to talks this Friday to discuss their overwhelming rejection of pay proposals from the Public Service Pay Commission aimed at tackling problems of staff recruitment and retention.
The Executive of the PNA will meet on 14 November to decide their next move.