Up to 80 hospital maternity units throughout Britain are to close or be merged because of a shortage of specialist doctors and midwives, according to senior health sources.

The NHS is now 1,600 specialists short of the number it needs to maintain childbirth services at full level. A report on the crisis, prepared by experts from three Royal Colleges, is now being studied by Alan Milburn, the Health Secretary. It warns that a major shake-up of childbirth services cannot be avoided.

The report, "Reconfiguring Maternity Services", has been written by a committee representing the Royal College of Obstetricians and Gynaecologists, the Royal College of Midwives, and the Royal College of Paediatricians and Child Health. While the report does not explicitly give a figure for closures, one of its authors said that dozens of smaller maternity units nationwide will be forced to close or merge.

A senior Royal College source said: "The number of units affected is likely to be around 80. It wouldn't mean that a small unit in a remote area that was 50 miles from the next unit would close, but it would mean that units that were closer to each other might have to merge. People would have to choose between having an older, smaller unit nearby or a better-equipped, safer unit a few miles away."

Dr Keith Dodd, a senior consultant paediatrician at Derbyshire Children's Hospital, said the situation would get worse because the majority of paediatricians in training are women, many of whom would opt to work part-time. "In reality, we need about 3,200 people and we are way short of that figure," he said.

The problem has been made worse by a shortage of around 2,500 midwives. According to the Royal College of Midwives, a third of maternity units fail to provide one-to-one care and half of all deliveries are performed by consultants.

The difficulties are exacerbated by the introduction of the European Working Time Directive which places strict limits on the hours doctors work and make it impossible for many maternity units to provide a round-the-clock service. Strict NHS rules which insist a consultant must always be on duty are proving increasingly hard to adhere to.

The Government has also placed a cap on the number of consultant posts that can be created. The Royal College of Obstetricians and Gynaecologists estimates that another 215 consultant posts need to be created. There are around 1,600 paediatricians in the UK but, according to the Royal College of Paediatricians, double that number would be required to provide 24-hour cover in line with the EU directive.

The acute shortage of staff on maternity wards has already resulted in a number of units in large teaching hospitals being forced to put a temporary bar on emergency admissions by ambulance.

Yesterday Mr Milburn conceded in an interview with the Independent on Sunday, that the issues raised by the report were exactly why he would be calling for the creation of a new "Beveridge Plan" at a health summit on Wednesday.

Mr Milburn said he was aware of the issues but felt they could no longer be dealt with in isolation. "The summit will create six working groups to modernise the NHS. Beveridge laid the foundations for the NHS's first 50 years. This plan has to be the foundation stone for the next 50 years."