The mum of motorcycle crash victim Harry Dunn has spoken of her hurt and upset at foul Foreign Office emails slagging off her family.
And shadow Foreign Secretary Lisa Nandy is demanding a full investigation into how the contents were leaked.
She is also trying to force Foreign Secretary Dominic Raab to face MPs tomorrow to explain himself.
The family made a subject access request for emails relating to the case which they say they had no intention of making public.
Mother Charlotte said: “Personal data is a very private thing.
“They were leaking to the press behind our backs to manage the story and take the sting out of the tail.
“That was an absolute punch in the guts for us and I have been tearful and upset ever since. I’ve not been able to sleep at all.”
One email says Charlotte’s behaviour was “excessive”.
Ms Nandy said: “Leaking confidential emails that describe a grieving mother’s reaction as “excessive” is absolutely unforgivable.
“For the Government to treat this family with such contempt is beyond belief.”
The emails were leaked after Mr Raab personally apologised to the family last week.
Harry, 19, died when his motorbike was hit by a car near RAF Croughton, Northamptonshire, in 2019.
Driver Anne Sacoolas, 43, later left for the US using diplomatic immunity.
The family are campaigning to have her extradited to the UK to face charges here.
The family’s spokesman, Radd Seiger, said Foreign Office officials had been engaged “in baseless keyboard warfare”.
In the documents FCDO staffers described Mr Seiger as “evil”, “aggressive” and “erratic”, despite admitting he had played a “media blinder”.
Another email said the family were so convinced “of everyone’s bad faith that it never crosses their mind that anything we are telling them might be true”.
Mr Seiger said: “I am more than happy to bear the brunt of any criticism, but to attack a bereaved, grieving mother who has never put a foot wrong in the campaign is scandalous.”
Mrs Dunn added: “Any attack on him is a direct attack on us. We just want justice for Harry. Nothing more, nothing less.
“There is something rotten in the FCDO that is preventing them from doing the right thing for us.”
The family has also received an apology from the FCDO’s top official Sir Philip Barton.
He wrote: “The digest contains some unprofessional and unacceptable language that you may find upsetting.
“I want to offer my sincerest apologies for the hurt that this may cause.”
An FCDO spokesperson added: “The views expressed by a small number officials were deeply inappropriate.”