And Ireland may get fined up to €100m because of it, as an EU directive clearly specifies that junior doctors should not be on duty for over 48 hours a week.
But some doctors allegedly work 70 hours, with many putting in over 100.
Last week, the European Commission raised a case against Ireland to the European Court of Justice on the issue, though its ruling will not become known until late June.
If the country is found to be in breach of the existing EU directive, Ireland could be fined over €100m.