Junior doctors at Tullamore Hospital are beginning a one-day strike this morning to highlight their grievances over a change in rosters.
The strike has threatened to spread to all major hospitals, with the Irish Medical Organisation (IMO) balloting its junior doctor members on strike action this week.
In Tullamore, non-consultant hospital doctors (NCHDs) in all departments, apart from Accident & Emergency, will take part in the action.
A spokeswoman for the Midland Health Board said patients had been notified that a number of procedures would be cancelled, so disruption should be minimal.
Junior doctors at Waterford Regional Hospital's paediatric unit have been striking since Thursday over the same issue and the action will spread to the entire hospital on Thursday if progress is not made.
The dispute centres around new rosters introduced by some hospitals in recent weeks. While they had reduced working hours, they had increased the number of hours worked outside 9 a.m. to 5 p.m. - the key training period for junior doctors.
The health boards and the Health Service Employers' Agency said that the reduction in working hours was to ensure compliance with the EU Working Time Directive and they criticised the strike action.
However, the IMO said that the changes would affect the standard of training, as it could reduce junior doctors' training time by as much as eight hours a week in some cases.
NCHDs do most of their training between 9 a.m. and 5 p.m., when they work with consultants and do ward rounds, according to Mr Fintan Hourihan, industrial relations director of the IMO.
He said that the average NCHD worked 77 hours a week, but only 4 per cent of this time was spent on formal training. "This would make it even worse."
The change in working hours would result in more junior doctors emigrating to get training elsewhere, he said.
The IMO is posting strike ballot papers to more than 3,000 NCHDs this week and the result will be known within three weeks.
Mr Hourihan said that the strength of feeling was running very high on the issue. "Doctors will not stay around if they are not getting the training," he said. "Fifty per cent of all NCHDs are brought in from abroad already."
Reports that junior doctors were opposing the changes because they would reduce their overtime pay were rejected by the IMO. "This is not about overtime. In fact, we are trying to reduce the number of hours worked outside the core hours," Mr Hourihan said.
