The European Commission is taking Ireland to court over working hours for junior doctors.
The EU Working Time Directive limits doctors to a 48-hour working week. The Directive was introduced back in 2003.
However many medics are working in excess of 80 hours per week.
The EC says whilst Irish law respects the requirements, in practice hospitals are not applying the rules and there has been insufficient progress.
Junior doctors went on strike earlier this year to highlight the issue.
The EC says it considers the situation a serious infringement which endangers the health of both the doctors and patients and is referring Ireland to the European Court of Justice.
Back in October, the Irish Medical Organisation (IMO) accepted proposals put forward to curb working hours.
It means hospitals could be hit with fines for allowing junior doctors to do shifts longer than 24 hours. The Health Service Executive (HSE) has agreed to eliminate the practice by the end of 2014.
But European Commission spokesman Jonathan Todd says Ireland is not doing enough to meet its own targets.
"We were only prepared to go along with that end of 2014 deadline of there were clear signs of progress actually being made on the ground towards reaching that objective - and unfortunetly we have not had those indications," he said.
"On the contrary, there are clear indications there are still very serious problems of over work" he added.