Junior doctors are forced to work an illegal number of hours and are not left enough time for training, their professional association has claimed.
One in three newly qualified doctors will find themselves working longer than is legal when they start their first job this week, the British Medical Association said.
The General Medical Council is also concerned that the pressures on young doctors to meet patient targets are leaving little time for education and training. It has launched a review of the pre-registration house officer year (PRHO) - the first year of a doctor's working life.
Since August 2001, rotas for PRHOs must not exceed an upper limit of 56 hours per week, as part of the move to bring all junior doctors towards the European working time directive limit of 48 hours by 2009.
Junior doctors' leader Trevor Pickersgill said: "Although working hours are slowly coming down, the pace of hospital life has intensified, with more acutely ill patients being treated and shorter stays in hospital."
The BMA junior doctors' committee said that at least one in three junior doctors works more than 56 hours a week and called on the government to negotiate a practical solution.
Medical schools also have to comply with an EU directive requiring them to teach students for six years or to have 5,500 hours of contact time.
Sir Graeme Catto, president of the GMC and dean of Guy's, King's and St Thomas's School of Medicine, said: "To date we have managed by including the PRHO year as officially part of the university remit." Young doctors cannot fully register with the GMC until they have completed this year.
Sir Graeme said: "Given that the universities have demonstrated little interest in the PRHO year and have no clear-cut way of keeping a tight grip on PRHOs who may be scattered across the country and are employees of a number of different trusts, this has not yet worked uniformly well."
Ken Fleming, head of the medical sciences division at Oxford University, welcomed the review. "These young doctors are in danger of being used as an extra pair of hands and losing out on their education," he said.
Nearly 5,000 medical students will start their first job this week.
The GMC has also published a new edition of Tomorrow's Doctors , updating standards for medical education in line with the Bristol inquiry.