Foreign doctors will have to prove they can speak English before being allowed to work for the NHS, the government has said.
A "loophole" that allowed medics with a poor grasp of the language to treat patients will be closed.
The new checks have been announced after cases in which foreign doctors were said to have provided sub-standard care.
The General Medical Council (GMC) welcomed the move, saying it would strengthen patient safety.
It had pushed for tougher tests after pensioner David Gray was killed in 2008 by German doctor Daniel Ubani who administered 10 times the normal dose of diamorphine.
Ubani admitted being exhausted after getting only a couple of hours sleep before starting his shift in the UK, and said he was confused about the difference between drugs used here and in Germany.
His poor English meant he was refused work by the NHS in one part of the country but was later accepted in Cornwall.
Those coming to the UK from outside the EU already face strict language tests. But there are fears that doctors from within the European Economic Area have been able to work for the NHS without being asked if they can speak English properly.
The Government is proposing to give the GMC new powers to prevent doctors from being granted a licence to practise medicine in the UK where concerns arise about their ability to speak English.
Ministers are also introducing a single national list which every GP will have to be on before treating NHS patients. Previously every Primary Care Trust held a list of GPs.
It is hoped the change will help protect patients by ensuring poor performers cannot slip through the gaps between local lists.
Health Minister Dan Poulter said: "By introducing these steps we will be able to put an end to doctors treating patients without proper checks on their language."
Niall Dickson, chief executive of the GMC, said: "Our position is clear - patients must be confident that the doctor who treats them has the right communications skills to do the job.
"If doctors cannot speak English to a safe standard then the GMC must be able to protect patients by preventing them from practising in the UK."
He added: "We have been working hard for some time to close this loophole in UK legislation which has caused so much concern to patients and their families and we are delighted that the government has decided to act."