New rules that reduce the number of hours that junior hospital doctors work come into force from today.
The European Working Time Directive was brought in six years ago to make sure that 48 hours is the most anybody can work in one week.
Junior doctors were initially excluded from the rule, but from today they should not be working any more than 58 hours a week.
However, over two thirds of trainee doctors in Ireland will still work longer than that until an agreement can be reached between their union, the Irish Medical Organisation, and the hospitals.
The doctors are angry at changes to their rosters, which would mean working new shift patterns, losing overtime pay and protected training time.
The health boards could face large fines for every day that the new rule is breached, but a compromise could be reached where the new hours are brought in gradually and doctors will average 58 hours a week.
