Harry Dunn, 19, died in August 2019 after his motorcycle was in a collision with a car driven by Sacoolas near RAF Croughton, an air force base in the English county of Northamptonshire that is used by the US military.

Sacoolas left Britain shortly after the accident, claiming diplomatic immunity from criminal prosecution and the US refused to extradite her.

The case led to diplomatic friction between Britain and the US as Dunn’s parents, with the support of the British government, campaigned for Sacoolas to be prosecuted.

Appearing at London’s Old Bailey court by videolink, Sacoolas denied causing death by dangerous driving but admitted the less serious charge.

Prosecutor Duncan Atkinson said after consideration at the “very highest level” and in close consultation with Dunn’s family, the decision had been taken not to proceed to trial.

Sacoolas will be sentenced in the week commencing Nov 28, and the judge, Bobbie Cheema-Grubb, ordered that she attend in person.

She was told by the judge that she had shown “weighty evidence of genuine remorse” by taking part in the court process.

“If the sentence is one that does not involve immediate custody, there is no barrier to her returning home after the hearing,” the judge said.