Talks between the Irish Nurses Organisation (INO) and the Health Service Executive (HSE) continued through the night over Cork's new maternity hospital.
The talks resumed at 12.30am after discussions yesterday failed to produce an agreement.
INO general secretary Liam Doran briefed a meeting of about 250 midwives on proposed staffing levels at the new €75 million Cork University Maternity Hospital last night before heading back into talks.
The rescheduled opening of the facility remains in doubt this morning.
The HSE has spent the past number of days trying to reassure INO representatives on how it proposed to increase midwifery and nursing numbers from 315 on opening to 375 as recommended by the Labour Court in its ruling.
Midwives going into last night's meeting were reluctant to discuss the latest clarification from the HSE, with some indicating that much would depend on the position taken by the Mr Doran.
Last Friday INO negotiators had recommended acceptance of a revised proposal on staffing from the HSE which would have seen management open 128 beds at the 144-bed hospital with a nursing complement of 315.
However, this was rejected by the midwives, with 98.5 per cent expressing opposition to moving to the hospital with 315 midwives and nursing staff because of concerns over patient safety.
INO members sought further clarification on how the HSE proposed to increase staff numbers over an eight-week period, although the HSE had promised weekly reviews with an overall review after eight weeks.