The head of the Royal College of GPs (RCGP) has said there needs to be a "radical review" of out-of-hours care to prevent European doctors flying to the UK to cover weekend shifts.
Following a fatal error at a Cambridgeshire health trust, Professor Steve Field said the college was concerned about the quality of care being offered to patients in some areas of the country.
In 2008, 70-year-old David Gray died after being given a massive dose of painkillers by German doctor Daniel Ubani.
Dr Ubani – flown to the UK to work – said extreme tiredness and only three hours' sleep contributed to his mistake.
Professor Field said: "The RCGP is worried about the quality of care provided for patients out-of-hours in some parts of the country.
"I am particularly worried about the use of doctors from Europe flying in to provide out-of-hours care and then flying back to their home countries to provide services there.
"Doctors from Europe who come to the UK to work in out-of-hours services must prove they are of the same quality as our home-grown doctors."
A spokeswoman for the Department of Health said: "Patient safety is paramount. The local NHS has a clear legal responsibility to provide safe, high quality out-of-hours care, and a failure to do so can result in action by both the NHS or the independent regulator.
"In line with European policy, the UK is required to recognise professional qualifications of EEA nationals throughout the European Union."