Patient safety could be at risk because doctors, dentists and nurses from the EU are not facing tough enough language tests, leading medics have said.
In just one year, 29 medics from the European Economic Area (EEA) faced allegations of "inadequate knowledge of English language", according to data obtained by the Royal College of Surgeons (RCS).
By contrast, just 10 doctors from outside the EU faced the same accusations during 2014/15, the figures obtained by the RCS from the General Medical Council also show.
Brexit negotiations pose an "excellent opportunity" to ensure language checks are up to scratch, the RCS said.
It added that under current EU rules, doctors coming to Britain from the EEA only have to show they have general English language skills.
But those wishing to work in the UK who come from further afield have to prove their language abilities in a clinical context - showing they can talk fluently about symptoms and equipment.
Professor Nigel Hunt, dean of the Faculty of Dental Surgery at the RCS, said: "We want the same rules to apply to all non-UK professionals, regardless of where in the world they come from."
Prof Hunt added: "The number of EEA doctors and dentists facing allegations relating to their communication skills is an issue we think the Government should be taking very seriously.
"Currently EU law makes it impossible to insist applicants demonstrate their English skills in a clinical setting. However post-Brexit negotiations offer an excellent opportunity to change this and ensure that testing is vigorous enough to ensure patient safety."
A Department of Health spokesman said: "Patient safety is of the utmost importance, and we expect all healthcare professionals working in the UK to have a good command of the English language.
"That is why we have tough rules, allowing the GMC and individual employers to test employees at and beyond the initial point of employment - and these cases represent just 0.002% of NHS staff."
Niall Dickson, chief executive of the General Medical Council, said: 'Our language requirements are among the toughest in the world, and we keep them under regular review to make sure they continue to be effective."