Julian Assange handed legal lifeline by London's High Court after ...

WikiLeaks founder Julian Assange has been handed a legal lifeline by the High Court in London where he is trying to appeal his extradition to the United States.

In a written judgement released on Tuesday, two of the court's justices did not make a final decision.

They said they'd give the US more time to provide assurances about several points "before making a final decision on the application for leave to appeal".

The justices wrote that if the US could not provide adequate assurances on three of nine points identified in the judgement, Assange would be granted leave to appeal.

They are: 

That Assange is permitted to rely on the US Constitution's first amendment (which protects free speech)That Assange is not prejudiced at trial or sentence because of his nationalityThat the death penalty is not imposed should he be convicted

Lawyers for the US have been given three weeks to provide the information.

"If those assurances are not given, then leave to appeal will be given and there will then be an appeal hearing," the justices wrote in the judgement.

"If assurances are given then the parties will have a further opportunity to make representations, and there will be a further hearing on May 20, 2024 to decide if the assurances are satisfactory, and to make a final decision on leave to appeal."

WikiLeaks' founder Julian Assange was arrested inside the Ecuadorian embassy in London in April 2019.(Reuters: Simon Dawson)

It means the 52-year-old Australian, who faces 18 criminal charges in the US, will remain in Belmarsh Prison for the time being — good news, for him perhaps — but in a blow to his case, the High Court justices dismissed six of the nine grounds his legal team had sought to appeal.

The charges relate to material published on Assange's WikiLeaks website in 2010, which detailed, among other things, war crimes committed by US forces in Iraq and Afghanistan.

At a two-day hearing last month, his lawyers argued all the information the Australian had published was in the public interest but that he was being targeted because he had effectively become the "spokesperson for a global political movement against the United States".

Assange's attempt to appeal represent his last legal avenue to avoid extradition in the UK justice system.

Although, even if the application to appeal is ultimately rejected, Assange's legal team has already flagged it will appeal to the European Court of Human Rights (ECHR), of which the UK is a signatory, which would likely delay it further.

While he could legally be extradited while the ECHR assesses his case, doing so would be unprecedented.

Julian Assange's wife Stella remained optimistic on Tuesday, despite the judgment ruling out many of her husband's appeal grounds.(Reuters: Toby Melville)

The information published on WikiLeaks was given to Assange by soldier-turned-whistleblower Chelsea Manning.

Assange was living in the United Kingdom at the time of publication, and most of the charges he faces are under the US's Espionage Act.

At the two-day hearing in February, Assange's legal team argued the Espionage Act had never been used to prosecute publishers before.

But barrister Clair Dobbin KC, acting for the US, told the court Assange and his WikiLeaks platform were not "ordinary journalists or publishers".

She said Assange had encouraged Manning to "steal" classified documents and that lives had been put at risk by the Australian's decision to "knowingly publish the materials with the names unredacted".

Manning was arrested in 2010 and later jailed for 35 years, but had her sentence commuted by then-US president Barack Obama, and was freed in 2017.