Alleged computer hacker Lauri Love fears he will die behind bars after Home Secretary Amber Rudd authorised his extradition to the US.
Mr Love, 31, who has Asperger syndrome, spoke of his fears as his father called for ‘British justice for a British citizen’.
Mr Love, from Stradishall, is alleged to have ‘stolen’ huge amounts of data from US agencies including the Federal Reserve, the US Army, the Department of Defense, Nasa and the FBI.
US authorities have been fighting for Mr Love, who lives with his parents, to face trial on charges of cyber-hacking, which his lawyers say means a sentence of up to 99 years in prison if he is found guilty.
The Home Office said Ms Rudd had ‘carefully considered all relevant matters’ before signing an order for Mr Love’s extradition on Monday.
Mr Love told the Daily Mail: “I don’t think much of my future life prospects. I face decades and decades behind bars and at worst I may die.
“We were kind of expecting this but it’s still a disappointment and a kick in the gut. I’ve got to watch my mental health now and make sure I have support.
“We will put as much as we can into the appeal.”
Mr Love, who could face the possibility of three separate trials in different jurisdictions, has 14 days to apply for permission to appeal against the decision.
Responding to the announcement, his father, the Rev Alexander Love,said: “I cannot begin to express how much sorrow it causes me.
“All we are asking for is British justice for a British citizen.”
It is alleged that between October 2012 and October 2013 Mr Love caused ‘millions of dollars’ worth of damage by placing hidden ‘backdoors’ within the networks he compromised, allowing hackers to return and steal confidential data.
Mr Love, who also suffers from depression and eczema, has said that a jail term in the US could cause his health to deteriorate and would lead to a mental breakdown or suicide.
Sarah Harrison, director of the Courage Foundation, which runs Mr Love’s defence fund and support campaign, said: “The US has ruthlessly persecuted hackers and digital activists for years and nobody expects that to improve under President Trump. “Theresa May set a good example by protecting Gary McKinnon (another alleged hacker with Asperger syndrome) back in 2012.
“For a Home Secretary in her government now to willingly send a brilliant and vulnerable UK citizen to Donald Trump’s America beggars belief.”
Tor Ekeland, Mr Love’s US lawyer and an expert in hacking cases, said Mrs Rudd was ‘boxed in’ by UK legislation and would have found it hard to justify blocking the extradition.
He told Iain Dale on LBC: “We were expecting this because under the law in the UK now this is essentially a rubber stamp for the Home Secretary – there’s not much latitude which she has.
“But he does have an appeal to the High Courts. We have one more shot at it in the UK.”
Mr Ekeland added that he feared that Mr Love would face a “way harsher environment” in the US following Mr Trump’s election.