Boris Johnson has urged the wife of a US diplomat allegedly involved in a road accident in Britain which killed a teenage motorcyclist to return to the UK to face questioning.
The Prime Minister said he was prepared to ring President Trump up and intervene personally on behalf of the family of 19-year-old Harry Dunn, who was killed when his motorbike collided with a car in August.
The accident happened close to RAF Croughton, an air base in Northamptonshire, which is used by the US military as a communications hub.
Mr Dunn, from Banbury in Oxfordshire, was hit by an Volvo SUV believed to have been driven by Anne Sacoolas, 42, whose husband Jonathan worked at RAF Croughton for the US government.
She has since left the UK but Northamptonshire’s Chief Constable Nick Adderley has called on the US government to waive her diplomatic immunity.
He said the police had "CCTV evidence" that the vehicle had left the air base and was “on the wrong side of the road" when it collided with Mr Dunn.
Under the 1961 Vienna Convention, diplomats and their relatives are immune from prosecution in the host country but their immunity can be waived by their home country.
Mr Johnson told reporters on Monday, 7 October: "I do not think that it can be right to use the process of diplomatic immunity for this type of purpose. I hope that Anne Sacoolas will come back and will engage properly with the processes of law as they are carried out in this country."
"If we can't resolve it then of course I will be raising it myself personally with the White House," Mr Johnson said.
Foreign Secretary Dominic Raab has already raised the case with the US ambassador, Woody Johnson.
Northamptonshire Police said the driver had "engaged fully" following the crash near RAF Croughton, a US Air Force communications station, and said "she had no plans to leave the country in the near future".