The Home Secretary has rejected a last-ditch appeal for him to block the extradition of Gary McKinnon (right) to the US on computer hacking charges.
Alan Johnson said he had considered demands for him to intervene in the case but had decided that the extradition would not breach Mr McKinnon's human rights.
“As the courts have affirmed, I have no general discretion,” he said in a statement.
Mr McKinnon's mother Janis Sharp said Mr Johnson and the Government “should hang their heads in shame”.
“To force a peaceful, vulnerable, misguided UFO fanatic like Gary thousands of miles away from his much-needed support network is barbaric,” she said.
“This is cruel and miserable.”
Mr McKinnon, from Wood Green in north London, is accused of breaking into the Pentagon's computer system but says he was just seeking UFO evidence.