While the court in London gave Assange permission to appeal, the Supreme Court must agree to accept the case before it can move forward.
The decision is the latest step in Assange’s long battle to avoid trial on a series of charges related to WikiLeaks’s publication of classified documents more than a decade ago.
US authorities want Australian-born Assange, 50, currently in jail in London as he awaits a ruling on his extradition, to face trial on 18 counts relating to WikiLeaks’s release of vast troves of confidential US military records and diplomatic cables which they said had put lives in danger.
“Make no mistake, we won today in court,” said Assange’s partner, Stella Moris, with whom he had two children while in the Ecuadorian embassy. “Our fight goes on, and we will fight this until Julian is free.”
In December, the High Court overturned a lower court’s ruling that said Assange should not be extradited because his fragile mental health meant he would be at risk of suicide.
While judges on Monday refused him permission for a direct appeal to the Supreme Court on their decision, they said his case raised an issue of legal importance that he could ask the UK’s top court to rule on.
This means the Supreme Court will have to decide whether it should hear his challenge. The ruling will stall any extradition from the UK for now.
The 18 offences Assange is accused of are 17 counts of espionage and one of computer misuse – relating to WikiLeaks’s release about 10 years ago.
Washington’s charges against Assange carry a maximum prison sentence of 175 years.
He denies any wrongdoing. His lawyers say he was acting as a journalist and is entitled to First Amendment freedom of the press protections for publishing documents that exposed US military wrongdoing in Iraq and Afghanistan.
Nick Vamos, a partner at Peters & Peters solicitors in London and a former head of extradition at Britain’s Crown Prosecution Service, said it was unlikely that the appeal would be granted. Assange can only take the case to the Supreme Court if the High Court rules that there are matters of “general public importance” to consider.
Amnesty International welcomed the decision to allow Assange to appeal to the Supreme Court, but raised concerns about the limited scope allowed by the High Court, which focused on US assurances that the Wikileaks founder would not face severe confinement conditions if extradited.
“Torture and other ill-treatment, including prolonged solitary confinement, are key features of life for many people in US federal prisons, including those imprisoned on charges similar to Assange’s,” Massimo Moratti, Amnesty International’s deputy director for Europe, said in a statement.
“The ban on torture and other ill-treatment is absolute and cannot be upheld by simple promises from a state that it won’t abuse people.”
Soon after WikiLeaks came to prominence, Sweden sought Assange’s extradition from the UK over allegations of sex crimes. When he lost that case against extradition in 2012, he fled to the Ecuadorian Embassy in London.
After relations with Ecuador soured, Assange was dragged out by British police in April 2019 and jailed for breaching British bail conditions, although the Swedish case against him had already been dropped.
US authorities then sought his extradition.
Even if the Supreme Court decides not to hear his appeal, the legal battle is far from over. The extradition must be approved by the home secretary, whose decision can also be subject to legal challenge.