London’s High Court is set to hand down its ruling on whether WikiLeaks founder Julian Assange will be able to appeal against extradition from Britain to the United States, in what could be his final legal challenge in British courts.

US prosecutors want to put Assange, 52, on trial on criminal charges relating to WikiLeaks’ high-profile release of vast troves of confidential US military records and diplomatic cables.

They argue the leaks imperilled the lives of their agents and there was no excuse for his criminality. Assange’s supporters hail him as a hero of journalism who is being prosecuted for exposing US wrongdoing.

Britain gave the go-ahead for his extradition in 2022, and he has since been trying to overturn that decision.

His first attempt to appeal against the transfer was refused, leading to a two-day hearing last month when his lawyers sought to reverse that judgment.

Two senior judges will hand down their ruling at 10.30am on Tuesday (9.30pm AEDT)

If Assange wins, a full appeal hearing will be held to again consider his challenge. If he loses, his last option would be an appeal to the European Court of Human Rights.

“This is it. DECISION TOMORROW,” his wife Stella Assange posted on X.

Julian Assange’s legal battles began in 2010, and he subsequently spent seven years holed up in Ecuador’s embassy in London before he was dragged out and jailed in 2019 for breaching bail conditions. He has been held in a maximum-security jail in southeast London ever since, even getting married there.

During the hearings in February, Assange’s team argued the prosecution was politically motivated and said he was being targeted for his exposure of “state-level crimes”.

They said former US president Donald Trump had requested “detailed options” on how to kill him.

Lawyers for the US said he was not being prosecuted for publication of the leaked materials, but for aiding and conspiring with former US Army intelligence analyst Chelsea Manning to unlawfully obtain them, then disclosing names of sources and “putting those individuals at grave risk of harm”.

WikiLeaks first came to prominence in 2010 when it published a US military video showing a 2007 attack by Apache helicopters in Baghdad that killed a dozen people, including two Reuters news staff.

Last week, Assange’s US lawyer said his legal team saw no indication of resolution to the case against him following a newspaper report the US Justice Department was considering allowing him to plead guilty to a reduced charge.

– AAP