Labour has written to the foreign secretary to press for answers about the involvement of the disgraced MP Chris Pincher in the government’s botched handling of the case of Anne Sacoolas, the US citizen who killed the British teenager Harry Dunn. The shadow foreign secretary, David Lammy, called for the publication of any correspondence between US authorities and Pincher – who was minister for the Americas at the time – over the decision not to object to Anne Sacoolas being flown out of the UK after the crash that killed Dunn in August 2019. Sacoolas, who was driving on the wrong side of the road when her car struck the young motorcyclist, was handed an eight-month suspended sentence by a judge at the Old Bailey last week and was disqualified from driving for 12 months. Pincher was under investigation in the summer of 2019 over misconduct allegations. Dunn’s family want to know if he was too distracted to stand up to the US when it used a loophole to exert diplomatic immunity for Sacoolas. Her husband was employed at RAF Croughton in Northamptonshire and is understood to have been working for the CIA. In a letter, Lammy called on the foreign secretary, James Cleverly, to commit to an inquiry into the affair and to provide details of what assurances the government had received that the US would act differently in future cases. Cleverly is also being asked why the Foreign Office did not provide official representation when Dunn’s family visited the White House in October 2019 for what they subsequently came to view as an “ambush” by Donald Trump. The then president had Sacoolas waiting in a room next door after British officials had called the family’s spokesperson days before to ask if his number could be passed on to Trump’s team. Cleverly said after last week’s judgment: “We have learned important lessons from this tragic incident, including improvements to the process around exemptions from diplomatic immunity and ensuring the US takes steps to improve road safety around RAF Croughton.” But in his letter, Lammy told Cleverly: “The Dunn family needs reassurance that this experience will not be inflicted on any other family ever again. The pain the Dunn family have had to endure, made worse by a series of failures in Foreign Office, must never be repeated. No other family can ever be allowed to go through this injustice again.”