After being denied an appeal on Friday to argue his case before the British Supreme Court, Gary McKinnon, who faces extradition to the United States for hacking into NASA computers, is making a last-ditch appeal to the country's Home Secretary Alan Johnson.

The basis of the appeal is a new confidential assessment outlining McKinnon's deteriorating health, and the potentially devastating effect extradition could have on him, according to a BBC report.

McKinnon now has less than two weeks to persuade Johnson to reconsider. His lawyers have said that failing that, they plan to make a final appeal to the European Court of Human Rights, according to the BBC. If none of these succeed, McKinnon could be on a plane to the United States this month.

The British home secretary has insisted that he does not have the power to halt the extradition, even though he is responsible for U.K. internal affairs and immigration, according to the BBC.

McKinnon, 43, is accused of hacking into 97 computers operated by the U.S. government, including those of the Pentagon, Army, Air Force and NASA. Authorities said his actions resulted in a shutdown of the Army's Military District of Washington network, containing more than 2,000 computers and resulting in $700,000 in damage.

McKinnon has maintained that he is simply a computer geek and only wanted to find evidence of alien life and UFOs.

McKinnon's lawyers say extradition would lead to "disastrous consequences" for his health, including possible psychosis and suicide. They claim McKinnon, who suffers from Asperger's syndrome, is in an “extremely fragile mental state.”

McKinnon's mother, Janis Sharp, who has been instrumental in his defense strategy, told the BBC that no other country would offer its citizens to the United States so readily “as sacrificial lambs,” just to safeguard a special political relationship.

“To use my desperately vulnerable son in this way is despicable, immoral and devoid of humanity,” she said.