The NHS could reach "breaking point" within the next few years due to increasing demands on the service, senior doctors said today.
Financial pressures may mean junior doctors do not get training posts within the NHS and fewer places could be available at medical schools.
This is despite extra burdens on the health service, including limits to doctors' working hours doctors, more hospital admissions and greater longevity, according to the study from the UK Royal Colleges of Physicians (RCP).
Those specialties dedicated to looking after very ill people are facing particular strain, it said.
Dr Andrew Goddard, RCP director of medical workforce, said the combination of factors was "adding further stress to a system which may reach breaking point within the next few years."
Junior doctors need jobs to go to, Dr Goddard added.
Today's report comes as the British Medical Association warned that senior doctors are facing cuts to the time they can devote to improving services, research, safety audits and training.