The Irish Medical Organisation is due to debate a timetable for possible strike action by junior doctors at its annual conference in Killarney later today.
The union is threatening to re-activate industrial action called off last year when it had reached agreement with health service employers to reduce working hours.
The IMO claims hours remain high, with non-consultants still working an average of 77 hours per week.
President Dr Mick Molloy said the Government was only now seeking costings for a report on the reduction of working hours which was published in January.