WikiLeaks founder Julian Assange has said it would be "politically impossible" for Britain to extradite him to the United States for espionage.
Mr Assange told the Guardian newspaper there was a "high chance" he would be killed if he was jailed in America.
US authorities are thought to be considering whether they could extradite him on espionage charges.
He is currently on bail facing extradition proceedings to Sweden on sexual assault allegations.
Mr Assange denies the claims and says the case is politically motivated.
His Wikileaks website has published tens of thousands of leaked US diplomatic cables.
Mr Assange said strong public support for him in the UK would make it difficult for the British to hand him over to the Americans.
"It's all a matter of politics. We can presume there will be an attempt to influence UK political opinion, and to influence the perception of our standing as a moral actor," he said.
"Legally the UK has the right to not extradite for political crimes. Espionage is the classic case of political crimes. It is at the discretion of the UK government as to whether to apply to that exception."
He also said that if he was extradited to the US, there was a "high chance" of him being killed "Jack Ruby-style".
This is a reference to the man who killed Lee Harvey Oswald before he was brought to trial for the murder of President John F Kennedy.