Foreign Secretary Dominic Raab has raised the case of Harry Dunn with his US counterpart as the teenager’s family head to London to “make our feelings known” during President Donald Trump’s latest visit to the UK.

The 19-year-old's family are demanding that American Anne Sacoolas, 42, who collided with Harry’s motorbike then fled to the US after claiming diplomatic immunity, return to face justice.

Harry Dunn died in a car crash in Northamptonshire in August. Credit: ITV News

A Foreign Office spokesperson said Mr Raab, who has been criticised by the Dunn family for his handling of the case, raised the issue with US Secretary of State Mike Pompeo when they met in London on Tuesday.

Mr Pompeo is currently in London while a Nato summit takes place.

“The Foreign Secretary again raised UK concerns about the tragic case of Harry Dunn,” said the spokesperson, adding that the UK would continue to press for Ms Sacoolas to “co-operate fully with the judicial process”.

Mr Dunn's parents also called on Boris Johnson to “press the family’s case for justice” when he meets Mr Trump during the summit.

Both men will be at an event hosted by the Queen on Tuesday evening for Nato leaders and Mr Dunn’s family plan to “congregate outside Buckingham Palace” to make “our presence known”.

President Trump spoke to reporters in London Credit: PA

Mr Trump was asked about the case by reporters in London ahead of meeting the Prime Minister.

The US President, who met the family when they flew to the US to put pressure on Ms Sacoolas to return, described the Dunns as “lovely people”.

Mr Trump repeated the US position that Ms Sacoolas had diplomatic immunity but said he had also met her, adding: “We’re trying to work something out.”

Mr Dunn’s family say they expect the Prime Minister to demand Ms Sacoolas’s return, to call for it publicly and then meet them to confirm he has spoken to Mr Trump about the issue.

Harry Dunn’s father Tim Dunn Credit: PA

Speaking on behalf of Harry’s mother Charlotte Charles and father Tim Dunn, spokesman Radd Seiger said: “Political leaders in the UK have made several public statements that they are doing all they can for Harry’s family.

"We have seen not a shred of evidence of that.

“Actions speak louder than words.

"We expect Mr Johnson to demand Anne Sacoolas’s return to the UK in his bilateral meeting with President Trump this week, to also call for that publicly, and then to meet with us to confirm that he has done so.”

It is understood that Harry’s parents have also expressed their “misery” to the Crown Prosecution Service over the time they have taken in deciding whether or not to charge Mrs Sacoolas.

Both Ms Charles and Mr Dunn have sent messages to a senior crown prosecutor, in which Harry’s mother spoke of her “utterly shattered heart”.

The family of Harry Dunn say they will 'make their presence known' outside Buckingham Palace. Credit: PA

Speaking of the CPS’s charging decision, Mr Seiger said: “For reasons unbeknown to the family, the CPS continue to delay authorising a charge.

"That delay must come to an end.

“There is no good reason for it that we are aware of.”

Responding to the criticism, a CPS spokesperson said: “We fully understand how difficult this must be for Harry Dunn’s family and the CPS is doing everything possible to reach a charging decision as soon as we can.

“Unfortunately, we are unable to tell the family how long that will take.

“Each case is different and the CPS has a duty to carefully consider all the available information in order to make an independent and objective decision.”

Mr Dunn died outside US air base RAF Croughton in Northamptonshire on August 27.

Ms Sacoolas initially co-operated with police but then claimed diplomatic immunity and fled to Washington DC and has refused to return.