The 39-year-old Australian was granted bail earlier this week on condition he provides sureties of £240,000.
But he has remained in Wandsworth Prison after Swedish prosecutors appealed against giving him bail.
Mr Assange is fighting extradition to Sweden where he faces sex allegations involving two women, which he denies.Curfew condition
He was granted bail by District Judge Howard Riddle at City of Westminster Magistrates' Court on Tuesday, pending extradition proceedings due to start on 11 January next year.
Conditions included the posting of a £200,000 cash deposit, with a further £40,000 guaranteed in two sureties of £20,000.
He was also told live under curfew at the home of journalist Vaughan Smith, founder of the campaigning Frontline Club.
However, the Swedish Judicial Authority has appealed against the bail decision.
The appeal is expected to be heard in Court 4 at the Royal Courts of Justice in London by Mr Justice Ouseley.
He is the judge who last week upheld bail for Shrien Dewani, whose wife was murdered on their honeymoon, following an appeal by South African authorities.'Politically motivated'
Mr Assange has received the backing of a number of high-profile supporters including human rights campaigners Jemima Khan and Bianca Jagger, and film director Ken Loach.
Mr Assange's website has published 250,000 sensitive American diplomatic cables, details of which have appeared in the Guardian in the UK and several other newspapers around the world.
He has come under criticism in the US where former Republican vice-presidential candidate Sarah Palin has said he should be hunted down like the al-Qaeda leadership.
Mr Assange argues that the allegations against him are politically motivated and are designed to take attention away from the material appearing on Wikileaks.
Mr Assange is accused of having unprotected sex with a woman, identified only as Miss A, when she insisted he use a condom.
He is also accused of having unprotected sex with another woman, Miss W, while she was asleep.