Junior doctors are to go on strike next week.
Non-consultant hospital doctors, who claim they are forced to work 24-hour shifts and 100 hours a week, have rescheduled their planned walkout over long hours.
The Irish Medical Organisation (IMO) said it was resuming its day of action and set a new date of Tuesday October 8 for the strike.
Eric Young, the IMO's assistant director industrial relations, said that the Health Service Executive (HSE) had failed to demonstrate that it was committed to addressing what it called a crisis.
"Ultimately the HSE wants us to trust them to resolve this issue but they have repeatedly failed to honour commitments on this issue going back a decade so it's just not realistic to expect us to take them on trust on this occasion," he said.
The IMO said all public hospitals in the country will be affected by the strike.
The union and the HSE had been involved in talks over the last fortnight in a bid to avert a strike and ease doctors' concerns over rosters.
The IMO said the HSE failed to offer satisfactory clarification on a number of issues.
Mr Young criticised a claim in a letter from the HSE that the executive had engaged for nearly a month.
"Attending meetings with no preparation to show and no ideas to offer to a decade old dispute does not count as engagement," he said.
"The HSE has wasted a decade on this issue and lost the trust of a generation of non-consultant hospital doctors and they have now wasted another month with the same indifferent approach."
Mr Young said a key issue was the refusal of the HSE to accept realistic sanctions for failing to comply with the European Working Time Directive.
"The HSE has to know that failure in implementation of EWTD will hurt them financially - there will be no financial consequences if they simply do their job. They've refused to accept that principle and that's a real issue for us in terms of agreeing a solution to the crisis," he said.
In the previous strike threat junior doctors said hospitals would be staffed at bank holiday or weekend levels for the one day of action.