Julian Assange won a significant victory in his battle against extradition to Sweden today, after judges allowed him to petition the supreme court.
The Wikileaks founder actually lost his appeal, but judges said it was of "general public importance" that his case be heard.
He now has 14 days to launch a written application for the supreme court to rule directly on whether the Swedish authorities had the authority to issue European arrest warrants.
The decision is a victory for civil liberties campaigners, who have long complained that the European arrest warrant allows for British citizens to be sent overseas too easily.
The news comes as MPs trying to overhaul Britain's extradition treaty with the US make their case in parliament.
The Commons will vote on the matter in backbench business time amid growing pressure about current arrangements.
Only 54 people have been extradited to Britain since 2004, compared to 123 people extradited the other way.
Mr Assange wore a dark grey coat, black jumper and a white open-necked shirt as he appearedm in court this morning. He is wanted for questioning by Swedish authorities over accusations of rape and sexual assault made by two Swedish women during a trip there in 2010 - claims he strenuously denies.
His arrival at the court this morning was met by a small group of demonstrators convinced the Swedish case is linked to US efforts to have the Australian sent to America.
Celebrity backers were also present, including campaigning journalist John Pilger.
Even if he loses the supreme court case, Mr Assange has a slim chance of appeal to the European court of human rights in Strasbourg.