A hearing at the High Court in London will determine if Assange will be allowed to leave Wandsworth prison after lawyers acting for Sweden challenged a British judge's order that he be freed under stringent conditions.
Sweden wants the UK to hand over Assange for questioning over claims that he sexually assaulted two women in Stockholm in August, but the 39-year-old Australian's supporters insist the process is politically motivated.
If released on bail, Assange will have to reside at the country estate of Vaughan Smith, a former British army officer who founded the Frontline Club, a media club where WikiLeaks has based part of its operations.
Despite Assange's arrest on December 7th, his whistleblowing website has continued to release US diplomatic cables that it has been leaked. Washington has been infuriated by the leaks, which have caused it great embarrassment.
The latest batch Thursday showed that a BP oil platform in Azerbaijan suffered a well blowout and a huge gas leak around a year and a half before the Gulf of Mexico oil spill.
In a highly charged court hearing on Tuesday, Assange was granted bail on
condition he pays a security of £200,000 pounds ($315,000 dollars), with an additional £40,000 guaranteed in sureties.
Celebrity supporters, including maverick US film director Michael Moore, British director Ken Loach, campaigning socialite Bianca Jagger and journalist John Pilger have helped put up the money.
Meanwhile, Assange's lawyer, Mark Stephens accused authorities on Wednesday of making it difficult for the website founder's legal team to meet him and prepare his case.
"I can't get access to him," he said. "I will not be able to take instructions from him."