Foreign doctors practising in the UK whose English skills are inadequate could be struck off amid fears that patients are being put at risk.
Newly-unveiled plans would also see senior medical staff ordered to ensure that all staff at their organisations have adequate language ability.
Concerns have been raised after cases in which foreign-born doctors were said to have provided sub-standard care.
Those coming to the UK from outside the EU already face strict language tests.
But some 23,000 doctors from within the area are said to have registered to work in the NHS without being asked if they can speak English properly.
Health Secretary Andrew Lansley said the moves, being put out for consultation, would help protect patients.
"It is absolutely crucial that we get this right," he said.
"Clearly if a doctor can't speak proper English then they won't be able to communicate effectively with their patients.
"It can also lead to situations where doctors put patients' safety at risk - the last Government knew this was a problem but failed to change the system to protect patients."
A 2010 report into foreign doctors warned that changes were urgently needed after David Gray, 70, died after he was given 10 times the recommended dosage of diamorphine by a Nigerian-born German locum .
Mr Lansley added: "We will create a legal duty that will mean doctors in hospitals and in the community will have to ensure that anyone hired is able to speak English and is suitably qualified and experienced for the role.
"This will create proper accountability and will leave no one in any doubt about our desire to protect patients."
Around 500 "responsible officers" at hospitals and other organisations will be tasked with checking language skills.
The Government also hopes to amend the General Medical Council's powers to make it easier for the body to take action if concerns are raised about a doctor's suitability.