Medical experts today followed UKIP in calling for EU regulations to be changed so that doctors coming to practise in the UK can be properly assessed.

Niall Dickson, Chief Executive of the General Medical Council, has written to health trusts to explain how there is a "gaping hole" in the registration system for doctors coming to work in the UK from EU member states. Currently such doctors do face less stringent tests than medical staff from other countries.

And alluding to the death of David Gray, who was killed in Cambridgeshire in 2008 when an overworked doctor from Germany accidentally administered the wrong dose of diamorphine, Mr Dickson told the House of Commons Health Select Committee: "Free movement of labour is fine but, in our view, patient safety trumps free movement of labour."

David Campbell Bannerman, UKIP’s health spokesman said: "UKIP has been calling for this for the past few years. The tragic case of David Gray shows that the EU is more interested in homogeneity than people's health. It is outrageous.

"The National Health Service is not the International Health Service. The Government discriminates against Commonwealth doctors in favour of doctors from the European Economic Area, whilst there is no way of legally checking their credentials.

"British people have died, and more will if this invidious system is allowed to continue. The Government should support the GMC, go to Brussels and demand that this directive be scrapped."