Moves by the European Union to establish a clear legal definition for active and inactive on-call time for medical staff and other essential services, and to abolish the opt-out from the 48 hour maximum working week, have become entangled in the wider political debate on the future of the 25 member bloc's economic policy.

Social affairs and health ministers were unable to reach agreement on the latest proposed changes to the EU's working time directive last week. Some argued that its flexibility was essential …