"The doctors' overtime bill is now costing an extra 240m a year and it is now clear that after four years of talks to try and reduce their working week, the doctors' overriding objective is to protect their huge overtime earnings, " said Gerard Barry, chief executive of the HSE-Employers Agency.

Barry accused the doctors' union, the IMO, of sabotaging the talks by refusing to give up the Monday-to-Friday working week, giving rise to huge overtime payments at weekends. A mid-ranking registrar is paid 56,710.68 a year but can double that in overtime.

But the IMO's Fintan Hourihan strongly denied sabotage, and said a new effort to break the logjam would be made this week at the Labour Relations Commission.

"We have offered to work an extended day from 8am to 7pm, " he said. "But junior doctors must have their core week of Monday to Friday, which is when consultants are in the hospital to provide training."