LONDON (Reuters) - Britain's Supreme Court will rule on Wednesday on whether to allow WikiLeaks founder Julian Assange's extradition to Sweden over alleged sex crimes, the latest chapter in the saga of the self-styled Internet whistleblower and bane of Washington.
Swedish prosecutors want to question Assange over claims of rape and sexual assault made by two female former WikiLeaks volunteers, and he has been fighting a lengthy legal battle against extradition since his arrest in Britain in December 2010.
The Supreme Court will say whether it agrees with his argument that the European Arrest Warrant (EAW) under which his extradition is sought is invalid. Two lower courts have already ruled that he should be extradited.
The former computer hacker gained international prominence in 2010 when WikiLeaks began releasing secret video footage and thousands of U.S. diplomatic cables about Iraq and Afghanistan, in the largest leak of classified documents in U.S. history.
That made him a hero to anti-censorship campaigners but a menace to Washington and other governments. Assange also faced widespread criticism that he had put lives at risk by blowing the cover of sources who spoke to diplomats and intelligence agents in countries where it was dangerous to do so.
Since then, WikiLeaks has faded from the headlines due to a dearth of scoops and a blockade by credit card companies that has made donations to the site almost impossible. Assange's personal standing has been damaged by the Swedish sex case and he has lost support from most of his celebrity backers.
Since his detention, he has mostly been living under strict bail conditions at the country mansion of a wealthy supporter in eastern England. His associates say that amounts to 540 days under house arrest without charge.
Assange's appeal hinges on a legal technicality rather than the substance of the allegations of sexual misconduct or his claims that the United States has been putting pressure on Britain and Sweden to take action against him.
His lawyers argue the EAW was invalid because it was issued by a prosecutor and not a judge or a court as required in Britain. Prosecutors acting for Sweden say different countries have different legal procedures which are allowable under the agreed EAW format.
The President of the Supreme Court, Lord Nicholas Phillips, is due to deliver a 10-minute judgment at 0815 GMT with a short explanation of how the seven judges reached their decision.
EUROPEAN APPEAL POSSIBLE
Even if the flamboyant Australian loses his appeal, which represents his final recourse in the British courts, he will not necessarily be on the next flight to Sweden as he can still take his case to the European Court of Human Rights (ECHR).
If that court agrees to hear his challenge, a decision which must be made within 14 days, he can lodge an injunction to have the extradition process put on hold, and it could be months at the very least before any conclusive verdict.
"If the ECHR declines to take the case then he will be extradited to Sweden as soon as arrangements can be made," Britain's Crown Prosecution Service said.
Should he win the case, a spokeswoman for Sweden's prosecutors said the EAW would still be valid in any other European country.
Meanwhile, British prosecutors have warned that a decision in his favor would set a dangerous legal precedent, with serious implications for other EU states wishing to secure extraditions from Britain.
Assange's personal travails have accelerated WikiLeaks' slide towards irrelevance since its heyday.
The suspected source of the site's biggest and most dramatic 2010 leaks, U.S. intelligence analyst Bradley Manning, is now facing 22 criminal charges which, if he is convicted, could land him in jail for life.
Manning's predicament has not encouraged any new sources to come forward, and to compound WikiLeaks' problems the blockade by the likes of U.S. credit card firms Visa and MasterCard has starved it of cash.
Assange once enjoyed support from socialite Jemima Khan, film director Ken Loach and crusading journalist John Pilger, but most of his high-profile backers have since distanced themselves from him. Many former friends and associates have turned against Assange also, describing him as a megalomaniac.
However, he still has loyal followers and rallies are planned in several countries in the wake of the court's verdict.
Instantly recognizable with his unusual white-blond hair, Assange has appeared in an episode of hit U.S. animation show "The Simpsons". He has also launched a talk show on Russia Today, a Kremlin-funded English language TV station.
(Additional reporting by Alistair Scrutton in Stockholm; Editing by Louise Ireland and Estelle Shirbon)