WikiLeaks founder Julian Assange’s extradition to the United States from Britain was put on hold on Tuesday after London’s High Court said the US must provide assurances he would not face the death penalty.

US prosecutors are seeking to put Assange, 52, on trial on 18 counts, all bar one under the Espionage Act, over WikiLeaks’ high-profile release of confidential US military records and diplomatic cables.

Assange’s lawyers in February sought permission to challenge Britain’s approval of his extradition, part of a more than 13-year legal battle in English courts.

In their ruling, two senior judges said he had a real prospect of successfully appealing against extradition on several grounds.

The court said in its written ruling that Assange arguably would not be entitled to rely on the First Amendment right to free speech as a non-US national and that, while none of the existing charges carried the death penalty, he could later be charged with a capital offence such as treason, meaning it would be unlawful to extradite him.

The judges said Assange had pointed to a comment by former US president Donald Trump who said in 2010, when discussing WikiLeaks, that “I think there should be like a death penalty or something.”

His case was at least arguable, the ruling said, citing “the calls for the imposition of the death penalty by leading politicians and other public figures”.

If the US assurances were not forthcoming by April 16, then Assange would be granted permission to appeal, the judgment said. A further hearing has been scheduled for May 20, meaning his extradition — which his campaign team said could have been imminent depending on the ruling — has been put on hold.

Wife hails decision

“Today’s decision is astounding,” Assange’s wife, Stella Assange, said outside the court. “The [US President Joe] Biden administration should not issue assurances, they should drop this shameful case that should never have been brought.”

Although Assange’s legal team were successful on some grounds, the court rejected his bid for an appeal on the basis that the case was politically motivated or that he would not receive a fair trial.

Assange’s many supporters hail him as an anti-establishment hero who is being persecuted, despite being a journalist, for exposing US wrongdoing and alleged war crimes.

The US says the WikiLeaks’ revelations imperilled the lives of their agents and there was no excuse for his criminality.

It has said Assange was charged for “indiscriminately and knowingly” publishing sources’ names and not his political opinions.