Medics have issued a warning over new rules limiting the number of hours junior doctors can work, after the EU regulations slashing the working week from 56 to 48 hours come into force.
The Royal College of Surgeons and pressure group RemedyUK have warned that the European Working Time Directive (EWTD) could wreak havoc if there is a second wave of swine flu in the autumn.
Dr Andy Thornley, chairman of the British Medical Association's junior doctors' committee, repeated fears that doctors may have been asked to lie about their hours and warned of potential gaps in rotas.
Dr Thornely said: "The NHS has had a decade to prepare for the introduction of the 48-hour week for junior doctors, yet it is clear to those of us that work in the NHS that many trusts have not properly prepared for this change.
"We are not reassured by government reports that the NHS is 97% compliant with the new working time regulation as we fear many junior doctors are being pressured to lie about their hours. Our members are worried about their training; many feel it has reduced in quality as working hours have been reduced.
"The future of the NHS depends on the production of the high quality consultants of tomorrow. This can not be done if standards of training are allowed to slide. Junior doctors are also deeply concerned that patient services could be affected in trusts that have not properly prepared for the working time directive. It is possible to meet training demands and maintain patient services. Solutions rely on hospital managers working with doctors to ensure that doctors' time is best used and all training opportunities are maximised."
However, NHS Employers insist the plans have been in place for a long time and the NHS will be able to cope.
Many doctors in the NHS are already working under the EWTD. So far, only 200 rotas out of 6,500 nationally have derogated in order to retain longer hours because they could not meet the August 1 deadline for implementing the EWTD, NHS Employers said.
The think tank Open Europe, which is calling for reform of the European Union, said the rules could cost the NHS the equivalent of 5,400 new doctors. It said the new cap on junior doctor hours will cost the NHS between £143 million and £293 million. For the same amount the NHS will spend complying with the new rules, it could employ between 3,835 and 7,858 additional junior doctors.