Two judges are set to declare on Monday whether they are satisfied by US assurances that Assange, 52, would not face the death penalty and could rely on the First Amendment right to free speech if he was tried for spying in the US
Assange's legal team say he could be on a plane across the Atlantic within 24 hours of the decision, but that he could also be released from jail, or find himself yet again bogged down in months of legal battles.
Assange has since been under house arrest, holed up in an embassy and held in jail since 2010. (AP PHOTO)
Protesters gathered outside the court early on Monday, tying yellow ribbons to the iron railings, holding placards and chanting "Free, free Julian Assange".
In a plea to US President Joe Biden, flags read "#Let him go Joe".
Assange's wife Stella was due in court with his brother and father.
She had previously said that Assange hoped to be in court for the hearing.
WikiLeaks released hundreds of thousands of classified US military documents on Washington's wars in Afghanistan and Iraq - the largest security breaches of their kind in US military history - along with swathes of diplomatic cables.
In April 2010 it published a classified video showing a 2007 US helicopter attack that killed a dozen people in the Iraqi capital, Baghdad, including two Reuters news staff.
The US authorities want to put the Australian-born Assange on trial on 18 charges, nearly all under the Espionage Act, saying his actions with WikiLeaks were reckless, damaged national security and endangered the lives of agents.
His many global supporters call the prosecution a travesty, an assault on journalism and free speech, and revenge for causing embarrassment.
Calls for the case to be dropped have come from human rights groups, media bodies and Australian Prime Minister Anthony Albanese, along with other political leaders.
Assange was first arrested in Britain in 2010 on a Swedish warrant over sex crime allegations that were later dropped.
Assange's lawyers will turn to the European Court of Human Rights if extradition is granted. (AP PHOTO)
Since then, he has been under house arrest, holed up in Ecuador's embassy in London for seven years and, since 2019, held in the Belmarsh top-security jail, latterly while awaiting a ruling on his extradition.
"Every day since the seventh of December 2010 he has been in one form of detention or another," said Stella Assange, who was originally part of his legal team and married him in Belmarsh in 2022.
If the High Court approves the extradition, Assange's legal avenues in Britain are exhausted and his lawyers will immediately turn to the European Court of Human Rights for an emergency injunction blocking deportation pending a full hearing by that court.
If the judges reject the US submissions, Assange will have permission to appeal his extradition case on three grounds, and the appeal might not be heard until 2025.
The judges might also have decided to consider not only whether Assange can appeal but also the substance of that appeal.
If they find in his favour in those circumstances, he could be released.
Stella Assange said that, whatever the outcome, she would continue to fight for his liberty.
If he was freed, she said she would follow him to Australia or wherever he was safe.
"We live from day to day, from week to week, from decision to decision. This is a way that we've been living for years and years," she told Reuters.
"This is just not a way to live - it's so cruel. And I can't prepare for his extradition - how could I?
"But if he's extradited, then I'll do whatever I can, and our family is going to fight for him until he's free."
with PA
