WikiLeaks founder Julian Assange on Monday won a legal bid to appeal against his extradition from Britain to the United States on espionage charges.

High Court judges Victoria Sharp and Jeremy Johnson said Assange had grounds to challenge the UK government’s extradition order.

Assange faces 17 espionage charges and one charge of computer misuse over his website’s publication of a trove of classified US documents almost 15 years ago.

The Australian has spent the last five years in a British high-security prison after taking refuge in the Ecuadorian Embassy in London for seven years.

Lawyers for Assange argued Monday the US provided “blatantly inadequate” assurances the WikiLeaks founder would have free press protections if extradited to America to face espionage charges.

Lawyer Edward Fitzgerald said prosecutors had failed to guarantee that Assange, who is an Australian citizen and claims protections as a journalist for publishing US classified information, could rely on press protections of the First Amendment of the US Constitution. (AP)