A Scottish computer expert who faces jail in the USA for hacking into US military networks has won permission to launch a fresh High Court challenge over moves to extradite him to America.

Lawyers for Gary McKinnon, 42, argued that his health would suffer and he would be at real risk of suicide if extradited.

They argued that as he was diagnosed with Asperger's Syndrome, a form of autism, he should not be considered a criminal, and that it was likely to lead to mental health issues or suicide should he be removed to the USA.

Two judges ruled that his case "merits substantive consideration" and granted him permission to seek judicial review of Home Secretary Jacqui Smith's decision last October that extradition should take place.

Lord Justice Maurice Kay and Mr Justice Simon, sitting at the High Court in London, said it might be that Ms Smith's decision was "unassailable" - but ruled that Mr McKinnon had an arguable case that should be tested in court.

Reacting to the news, Gary's mother, Janis Sharp, said: "We are overjoyed that the British courts have shown sense and compassion by allowing our son Gary, a young man with Asperger's syndrome, this judicial review.

"We have always been outraged by the Home Office's decision to have him extradited to stand trial in a foreign land where he would face an out of proportion sentence for what is essentially a crime of eccentricity.

"We also have high hopes for a just outcome of the decision to be made by Keir Starmer, the Director of Public Prosecutions, on whether Gary can be tried in the UK.

"Perhaps now that Obama is in power in America, our world might really become a more compassionate place where consideration, a sense of perspective and individual’s human rights are brought to the fore."

Mr McKinnon signed a statement accepting that his hacking constituted an offence under the UK's Computer Misuse Act 1990, and the new director of public prosecutions is considering a request for Mr McKinnon to be prosecuted in Britain rather than the US.

His full application for judicial review is expected to be heard after March 16, the date by which time the decision on whether to prosecute him in the UK will have been made.