WikiLeaks founder Julian Assange has been granted the right to ask the United Kingdom’s Supreme Court to overturn an order extraditing him to Sweden, where he’s being investigated on rape charges.

A High Court said on Monday that it felt “constrained” to say that the case raised “a question of general public importance” beyond Assange’s individual circumstances but decided that Assange may proceed to ask the Supreme Court for permission to appeal his extradition ruling, according to the BBC. However, one of the High Court judges asserted that Assange’s chance of succeeding in the Supreme Court was “extraordinarily slim.”

Last February, Assange lost an effort to fight extradition to Sweden, where he faces questioning over sex-crimes allegations. He appealed that decision, but a High Court rejected that appeal last month. An appeal to the Supreme Court is his last chance to fight the extradition.

Assange has not been charged with any crime in Sweden, and used that fact as his primary defense in his earlier appeal to the High Court. Assange’s defense attorneys also asserted that Sweden’s request for his extradition was invalid because the prosecutor was “working for the executive” and was therefore not a proper judicial authority.

Mark Summers, an attorney for Assange, has told the court that, “Public prosecutors should not, in any circumstances, be permitted to issue [European arrest warrant]s.”

The High Court rejected both of those arguments and ordered that Assange must return to Sweden.

Assange then sought permission from the High Court to appeal to the Supreme Court. In order to do so, his attorneys had to show the High Court that his case related to a matter of public importance that went beyond Assange. The High Court refrained from asserting that his case met this criteria, but nonetheless gave him permission to ask the Supreme Court directly to hear his appeal.

Assange has 14 days to submit a written petition to the Supreme Court. If the court refuses to hear his appeal, he has no more avenue for redress and will be extradited to Sweden. If he is granted an appeal hearing, that appeal will likely take place at the Supreme Court around May next year.

Assange is being sought for questioning in Sweden on rape and coercion allegations stemming from sexual relations he had with two women in that country in August 2010. One woman has claimed that Assange pinned her down to have sex with her and intentionally tore a condom he wore. The second woman claims that he had sex with her while she was initially asleep, failing to wear a condom despite repeated requests for him to do so. Assange has disputed their claims.

Assange was arrested in Britain last December, just nine days after WikiLeaks began publishing from its cache of more than 250,000 leaked U.S. State Department diplomatic cables, which were trickling out at a rate of about a hundred a day. Nine days after that, Assange was released from jail on $300,000 bond.

Assange has denied any wrongdoing, asserting that the sex in both cases was consensual.

In the High Court’s rejection of his initial appeal, the judges noted that in the case of the second woman, “it is difficult to see how a person could reasonably have believed in consent if the complainant alleges a state of sleep or half-sleep” and that given that the woman had insisted on Assange wearing a condom, “consent would not have been given without a condom.”

Defense attorneys have claimed that Assange would not get a fair trial in Sweden, because rape trials in that country are sometimes held behind closed doors. They have also argued that Assange could somehow find himself extradited to the United States, where, they theorize, he could face execution for leaking secrets.

Assange has been living under house arrest in the large country estate of Vaughan Smith, whom the Guardian newspaper has described as “a former army officer, journalist adventurer and right-wing libertarian.” Assange has been allowed to remain free on bond, reporting to police every evening in person and honoring a curfew, while he awaited the outcome of his appeal.

Photo: Julian Assange (center) speaks to the media, flanked by his lawyers Mark Stephens (left) and Jennifer Robinson after making a appearance at Belmarsh Magistrates’ Court in London, Jan. 11, 2011. Matt Dunham/AP