WikiLeaks’ Julian Assange on Tuesday will appeal against a British court ruling that he be extradited to Sweden to face rape allegations.
The Australian founder of the whistleblowing website will attempt to reverse the February ruling in a two day hearing at the High Court in London.
Assange, 40, was arrested in December after two Swedish women accused him of sexual assault – allegations that Assange denies.
Swedish authorities want to quiz him over the sex assault claims, although he has not been formally charged.
However, a judge rejected arguments by Assange's defence team that he would face an unfair trial in Sweden that would breach his human rights.
The rape allegations emerged as WikiLeaks was in the process of releasing a huge cache of leaked US diplomatic cables.
It was the site's latest dump of US government documents and infuriated Washington.
US authorities opened a criminal investigation against Assange in July last year but are yet to formally bring any charges against him.
Assange has claimed his greatest fear is being extraditied to the US, where his lawyers argued he could be sent to the Guantanamo Bay detention facility or face the death penalty.
Assange’s court hearings in England attracted scores of journalists and celebrity supporters, including British socialite Jemima Khan and human rights campaigner Bianca Jagger.
After judge Howard Riddle rejected Assange’s lawyers' arguments during the extradition hearing at Belmarsh Magistrates' Court in London, Assange lashed out at the decision and blamed the European warrant system under which he was arrested.
"It is a result of the European Arrest Warrant system run amok. There was no consideration during this entire process as to the merits of the allegations against me," he told reporters after the ruling.
Assange has signalled that he is prepared for a lengthy court battle in the Supreme Court should he lose this week’s appeal.
Since December, the former computer hacker has been living under strict bail conditions, including wearing an electronic ankle tag and reporting to police every day.
He is under house arrest at a 10-bedroom Norfolk mansion, set on 650 acres, called Ellingham Hall.
It belongs to his friend, Vaughan Smith, director of the Frontline media club.
Despite the restrictions, at the country estate on Sunday Assange managed to celebrate his 40th birthday, which was on July 3. More than 100 guests were invited to a party, according to Smith.
Brad Pitt and Angelina Jolie and US Vogue editor Anna Wintour were apparently invited to the bash at the mansion, where a huge marquee was erected.
Party invitations included instructions on where to land helicopters and private jets.
Smith told the Independent: “You're only 40 once.”
WikiLeaks infuriated Washington with its release of classified documents, including around 250,000 US diplomatic cables and thousands of secret files about the wars in Afghanistan and Iraq.
US soldier Bradley Manning has been accused of leaking documents to the whistleblower site and is in a US military prison awaiting a possible court martial on charges that include "aiding the enemy."
US Vice President Jo Biden has slammed Assange as a "hi-tech terrorist", but he has also won many admirers – his website is among the nominees for this year's Nobel Peace Prize, due to be announced in October.
Last week it emerged a £850,000 book deal Assange signed to write his memoirs had collapsed.
WikiLeaks Versus the World: My Story had been due to be published as part of a lucrative deal with Canongate and Alfred A Knopf.
But fears that the US government could use the details against him, forced Assange to abandon the book.
In another blow, Visa has now closed a donation channel to WikiLeaks after a payment processor briefly accepted money transfers to the site.
Visa and MasterCard were two of several financial and Internet service companies that severed ties to WikiLeaks following its disclosure of thousands of confidential U.S. documents.
Assange has claimed the seven-month-long blockade has cost his online group millions.
A company spokesman said: “As soon as this came to our attention, action was taken with the suspension of Visa payment acceptance to the site remaining in place.”