IF JULIAN ASSANGE is feeling nervous in the lead-up to his High Court appearance in London this week, he is not showing it.

The WikiLeaks founder was reported to be celebrating his 40th birthday last night, with an extravagant party before his court case, where he will fight extradition to Sweden on sex charges.

Party time ... Julian Assange is turning 40. Credit:Reuters

The venue for the party was never in doubt. As part of his bail conditions, he is required to wear an ankle security tag and reside at the 10-bedroom Ellingham Hall in rural Norfolk.

What seems rather more surprising is the guest list and, if reports in the British press are to be believed, the A-list celebrities who might turn up. Speculation in The Independent suggested that Oprah Winfrey, Brad Pitt and Angelina Jolie (last seen in Malta, where the former is shooting a movie), Johnny Depp (who spends most of his time in France) and Anna Wintour (the Manhattan-based editor of US Vogue) are among those who could be trying to find their way to the property.