An autistic British man has received a one-year jail sentence for planning to kill President-elect Donald Trump at a Las Vegas rally in June.

Michael Sandford, 20, attempted to steal a gun from a police officer during the rally, before telling agents he wanted to kill Mr Trump.

He pleaded guilty to being an illegal alien in possession of a firearm and disrupting an official function.

Sandford told the court he “felt awful” about what he did.

“I know saying sorry is not enough,” he said.

“I wish there was some way to make things better. I have cost taxpayers so much money. I feel terrible.”

Sandford, from the British county of Surrey, had been living in the US for 18 months when he hatched the plan to kill Mr Trump.

He had been living out of his car and, according to testimony from his mother, been put on suicide watch numerous times in the past year.

Lynne Sandford believes her son may commit suicide inside a UK jail. Photo: Getty

Lynne Sanford travelled to the US from England for the trial, having campaigned to have her son deported back to the UK for his sentence.

The young man, who also suffers obsessive compulsive disorder, depression, seizures and Crohn’s disease, allegedly drove to a firing range to learn how to shoot a gun.

But on the day, Sandford was not able to get hold of the policeman’s firearm, and no shots were fired.

The judge presiding over the case told Sandford he was in need of medical help and should not be ashamed.

“You’re not a hardened criminal. You’re not evil or a sociopath like a lot of people we have,” Judge Mahan said.

“I don’t think you wanted to kill anybody. This was just some crazy stunt that your mind told you to do.”

Since Sandford has spent six months in custody already, he is expected to only have to serve another six.