LONDON - The extradition trial of Julian Assange, the mastermind behind the WikiLeaks Web site, opened on Monday with the 39-year old Australian placidly watching from the plaintiff's bench as his lawyers argued against sending him to Sweden to face sexual assault allegations.

With his celebrity supporters present in the courtroom, including Bianca Jagger and the socialite Jemima Khan, Assange, wearing a dark suit and purple tie, scribbled down notes and settled in for what is set to be the two-day hearing.

British lawyers representing Swedish prosecutors argued for Assange's extradition over allegations of rape, molestation and unlawful coercion lodged by two women who entered into brief relationships with Assange in Sweden last August.

Assange has denied said any wrongdoing, insisting he had consensual sex with both women.

Geoffrey Robertson, one of Assange's lead attorneys, argued that Assange could not receive a fair trial in Sweden in part because rape cases there are heard in private. Conducting such a case in secret, without press and the public present, he argued, "risks a flagrant denial of justice."

Given the broad laws governing extradition between European Union nations - which are structured to allow expedited extraditions -- experts say Assange faces a hard-fought case. His lawyers, however, were challenging the Swedish petition on multiple grounds.

They argued that Sweden should not have requested Assange's extradition because prosecutors there have not yet officially filed criminal charges against their client, instead issuing a warrant based on their desire to question Assange in connection with the allegations.

They have also suggested that the case is politically motivated, one of the rare justifications for refusing inter-European extradition requests. The defense asserts that the allegations against Assange amount to a conspiracy that would end with Assange being extradited to the United States to face charges for the leaking of secret State Department documents on the Internet.

The lawyers acting on behalf of Swedish prosecutors dismiss the conspiracy theory as false and unfounded.

Though the hearing is set to conclude on Tuesday, most analysts believe the judge will not issue a written verdict in a week or two. After that decision comes down, both parties will have the right to appeal to Britain's high court in a process that could drag on for months.

On Monday, about a dozen Assange backers gathered outside the Belmarsh high-security prison, where the court is being held. Some were wearing orange Guantanamo Bay prison outfits, while others wielded placards reading "don't shoot the messenger," and "the truth has been raped."