Lawyers for a 20-year-old British man accused of attempting to shoot Donald Trump at a Las Vegas casino plan to submit evidence of his medical health to US authorities in an appeal for clemency.
Michael Sandford is due to stand trial later this month over an incident at a rally on June 18 in which he allegedly tried to grab a policeman's gun to attack the Republican presidential candidate.
But his mother, Lynne Sandford, said her son suffers from a variety of mental health issues including autism, anxiety, depression and anorexia, and said he would not have foreseen the consequences of his actions.
She said: "I accept that Michael has tried to do a bad thing but he is mentally ill and is not a bad or dangerous person.
"Michael is extremely vulnerable and I don't think he will survive being incarcerated in a US prison if he has to serve his sentence there."
Saimo Chahal QC, a human rights lawyer from Bindmans who is representing the family, said they hope the trial date can be adjourned to give them time to gather medical evidence.
They have also been in contact with the Foreign Office and are keen to get Foreign Secretary Boris Johnson involved in the case.
Ms Chahal said: "We are regularly in touch with the public defender's office in Nevada. Our main aim would be to try and secure Michael's repatriation to the UK so that he can be assisted in a medical facility.
"Michael has a number of psychological and psychiatric conditions, some possibly yet undiagnosed. The best place for Michael would be to come back to the UK to receive medical treatment.
"At the moment there is a trial date listed for August 22. We hope that that trial will be adjourned so that we can gather together psychological evidence and psychiatric evidence at this end and submit it to the public defender's office."
Sandford faces three charges, to which he has pleaded not guilty - of disrupting government business and official functions, being an illegal alien, and possession of a gun.
But Ms Chahal said it was unclear whether he actually understands what he has been accused of because of his Asperger's syndrome, OCD and other psychological conditions.
She said: "There is a question mark over whether he's really fit to plead and to undergo the trial process in the States."
Sandford's team are now commissioning an independent mental health report which they hope to present to US authorities as part of a plea bargain.
Ms Chahal said: "What we very much hope is that there won't be a trial. Our best aim is for Michael to be repatriated back to the UK before he is sentenced."
She added: "It is a very unusual situation, pretty much a one-off situation, but we're optimistic that we will be able to influence the legal process by submitting evidence and making clear to the public defender's office that Michael does have all of these psychological and psychiatric conditions.
"We understand that there isn't a facility in the state of Nevada which would be able to accommodate Michael's conditions and therefore we will be making out a very strong case that he should be returned to the UK."
Ms Sandford, from Dorking, Surrey, said her son accepts he has to be punished for what he is alleged to have done but argued that he does not fully appreciate its gravity, saying autistic adults can have the "insight and behaviour of a small child".
The 42-year-old said: "Although he has got a man's body, he is still very much a child. He is very emotionally vulnerable - he still loves to watch Peppa Pig, so that is not a normal 20-year-old."
Ms Sandford described him as very "passionate, considerate and kind" but said he was sectioned at 14 after various mental health issues were diagnosed.
Sandford travelled to the US around 18 months before his arrest, and over the last year his mother said she has only had "sporadic" contact with him, reporting him missing after she did not hear from him for a week.
She does not know what triggered his alleged actions, saying he has always been a "very private, very insular person" and that his autism gives him a different perception and understanding of the world.
Sandford is being kept "shackled and handcuffed" in a Nevada prison, has been on suicide watch for the last three weeks, and is spending 22 hours a day isolated in his cell, his mother said.
When she spoke with him two nights ago, he was "extremely distressed and distraught".
Ms Sandford said: "He kept breaking down and sobbing on the phone, saying 'Please, please, I just want to come home'.
"He's very remorseful, he's profusely apologetic for any problems that he's caused. He deeply regrets any embarrassment to the family and he's just in a really bad way.
"He's just very emotionally fragile, very vulnerable, very frightened and very bewildered."
Ms Sandford has written a number of letters to her son, which she said he reads "over and over again because there is nothing else to do", but he is not allowed to write back, and she said he is desperate to come home and get help.
She is not allowed to visit him in person but hopes to go out for his trial, which will be heard in a Las Vegas federal court. A pre-trial hearing is scheduled for August 11.
Ms Sandford has raised more than £20,000 through a crowdfunding campaign to pay for his legal fees, mental health reports and to help her fly out to the US to support her son.
She said: "It's been a horrendous time for both us (his family) and for him, very difficult, very distressing for all concerned, but I've confirmed to Michael that we haven't abandoned him, we love him and we will help him to get the help he needs."
The campaign, launched through Crowd Justice, is at https://www.crowdjustice.co.uk/case/michaelsandford/