A judicial review of the planned extradition of Nasa and Pentagon hacker Gary McKinnon has been set for 25 and 26 May.
The two-day hearing will examine the decision made last month by home secretary Alan Johnson that he cannot intervene in the extradition process, which is set to see McKinnon tried in the US. The news was revealed by his mother, Janis Sharp, on her Twitter page.
McKinnon has admitted to the hacking, but said he was looking for evidence of UFOs rather than trying to cause damage to US government computers.
He suffers from Asperger's syndrome, a form of autism. His lawyers have argued he is in a "very poor mental state" as a result of the "ongoing pressure of these proceedings".
The hearing is likely to take place close to the date of a general election. The Conservative party has highlighted problems in the extradition treaty, insisting it should be modified in McKinnon's favour.
The British government initially approved McKinnon's extradition in 2006. The UK authorities decided not to prosecute McKinnon, even though his alleged crimes occurred in the UK, because most of the evidence and witnesses are in the US.
Last November, the powerful Home Affairs Select Committee of MPs stated that it was against McKinnon's extradition.
In a letter to home secretary Alan Johnson, committee chairman Keith Vaz cited McKinnon's "precarious state of mental health". He wrote: "The committee is of the view that he should not be extradited to the USA and that you [Johnson] should exercise your discretion in this case."
McKinnon also has a number of high-profile celebrity supporters, including the musician Sting, and last year gained the support of the tabloid Daily Mail newspaper, which ran a series of headlines against his extradition.