Judge Vanessa Baraitser said she had refused his extradition to the United States because of fears that he could commit suicide.

An appeal is expected to be mounted against the ruling, which comes after weeks of hearings at the Old Bailey last year and campaigning by supporters of Assange and others who have decried US charges against the him as an attack on press freedom.

The case against the 49-year-old relates to WikiLeaks’s publication of hundreds of thousands of leaked documents about the Afghanistan and Iraq wars, as well as diplomatic cables, in 2010 and 2011.

Prosecutors say Assange helped the US defence analyst Chelsea Manning breach the US Espionage Act, was complicit in hacking by others and published classified information that endangered informants.

Assange denies plotting with Manning to crack an encrypted password on US computers and says there is no evidence anyone’s safety was compromised.

His lawyers argue the prosecution is politically motivated and that he is being pursued because WikiLeaks published US government documents that revealed evidence of war crimes and human rights abuses.

At the weekend, Assange’s partner had said a decision to extradite the WikiLeaks co-founder to the US would be “politically and legally disastrous for the UK”.

Stella Moris, who has two children with Assange, said a decision to allow extradition would be an “unthinkable travesty”, adding in an article published by the Mail on Sunday that it would rewrite the rules of what it is permissible to publish in Britain.

“Overnight, it would chill free and open debate about abuses by our own government and by many foreign ones, too.”