A London court has ruled the Australian journalist cannot be extradited to the US because of his mental health and a risk of suicide should an extradition proceed.

Wikileaks founder Julian Assange (49) was the subject of an extradition request by US authorities following the publication of thousands of classified documents in 2010 and 2011.

Judge Vanessa Baraitser refused the request at the Old Bailey today however because of fears Assange could take his own life.

The US government, which will appeal the decision, had indicted the journalist on 17 espionage charges, with prosecutors also accusing him of computer misuse in the 2010 publication of intelligence and diplomatic documents.

If sentenced, Assange would have faced a potential prison-term of 175 years in the US. He will instead be taken back to Belmarsh Prison, with an application for bail expected on Wednesday.

Judge Baraitser said the US government was incapable of preventing a suicide attempt by Assange, despite meeting the tests for extradition.

“The overall impression is of a depressed and sometimes despairing man fearful for his future,” she said.

“Faced with the conditions of near total isolation without the protective factors which limited his risk at HMP Belmarsh, I am satisfied the procedures described by the US will not prevent Mr Assange from finding a way to commit suicide and for this reason I have decided extradition would be oppressive by reason of mental harm and I order his discharge.”

Assange’s fiance and mother of their two sons Stella Moris wept when the judgement was read out, whilst the accused closed his eyes.

Outside the court, Morris called on the US president to “end this now”.

“Mr President, tear down these prison walls,” she said. “Let our little boys have their father. Free Julian, free the press, free us all.”