A 20-year-old British man accused of attempting to shoot Donald Trump at a Las Vegas casino will plead guilty to lesser charges when he appears in court, his mother has said.

Michael Sandford, from Dorking, Surrey, is due to stand trial later this month over an incident at a rally on 18 June in which he allegedly tried to grab a police officer’s gun to attack the Republican presidential candidate.

But his mother, Lynne Sandford, told ITV News London he has signed a plea agreement, and the family’s lawyer is hopeful the trial will be adjourned.

“I was very relieved that he signed it,” Sandford said. “It was a bit of a battle because he is quite headstrong. But we all laid the options out there for him on the table and, of course, it is a gamble.”

Mrs Sandford previously said her son was extremely vulnerable and had various mental health issues including autism, anxiety, depression and anorexia. She said he would not have foreseen the consequences of his actions.

According to ITV News London, Michael Sandford has agreed to plead guilty to being an illegal alien in possession of a firearm and disrupting government business. He is expected to enter his plea on Tuesday before a US district judge.

Mrs Sandford added: “There’s no certainty. But he has signed the plea agreement. Now we have to wait to see if the judge will accept it and hopefully it’s the end of one stage and the beginning of another stage. Every stage is a stage closer to him being able to come home.”

The family’s lawyer, Saimo Chahal, said she is also hopeful a psychiatric report will play a key part in the defence.

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.”