Foreign doctors face GMC's English language tests
New powers allowing the medical regulator to check doctors' English language skills have come into force.
Previously only doctors from outside Europe could have their language skills tested by the General Medical Council (GMC), but this has now been extended to European doctors coming to Britain.
The GMC hailed the change in law as an "important milestone".
Ministers said "for the first time ever" there was now a "full system of checks" of doctors' language skills.
The change gives the GMC the power to ask European doctors for evidence of knowledge of English, and to order them to have a language test if "serious concerns" are raised about them.
GMC chief executive Niall Dickson said: "This is an important milestone in creating better, safer care for patients.
"Everyone has a right to expect to be treated by doctors who can communicate effectively in English and this will help us achieve this."
Mr Dickson said that under European law the GMC was not allowed to check every doctor, but said the change was a "vital first step".
He said it did not "absolve" medical employers of their duties to check doctors were "qualified and competent".
The risk of a doctor not being fluent in English was highlighted by a lethal mistake made by Dr Daniel Ubani, a German doctor doing an out-of-hours shift who gave a lethal dose of a painkiller to patient David Gray.
As a German citizen he was able to register to work in the UK without passing a language test.
At the end of April, there were 27,641 doctors registered with the GMC who had qualified in European countries.
Health Minister Dan Poulter said: "For the first time ever, we have a full system of checks in place to prevent doctors working in the NHS who do not have the necessary knowledge of English from treating patients.
"This is a huge step forward for patient safety. I am pleased to have played my part in making this happen."