Judge Vanessa Baraitser delivered her verdict at London’s Old Bailey court on Monday, saying she was alarmed by the effect incarceration in Britain’s Belmarsh prison has had on the 49-year-old Australian activist’s mental health.

She feared that the harsh confinement Assange potentially faces in the US while awaiting trial could worsen his health and lead to self-harm.

“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,” she told the court.

The US government now has 14 days to lodge an appeal.

If the appeal is successful, the case could be heard at the UK Supreme Court and European Court of Human Rights in Strasbourg, France.

“We will continue to seek Mr Assange’s extradition to the United States,” a US Department of Justice statement said, adding that the United States had won on all the legal points including arguments relating to freedom of speech and political motivation.

The decision by the District Judge does not mean Assange can be automatically freed from prison.

A decision on Assange’s bail conditions is due to be made on Wednesday.

Assange, wearing a suit a blue scarf, wiped his brow following the verdict while his partner and mother of his two children, Stella Moris, wept in court, the Press Association reported.

Whistleblower Edward Snowden was pleased with the result and gave thanks to Assange’s supporters.

“Thank you to everyone who campaigned against one of the most dangerous threats to press freedom in decades,” he wrote on Twitter.

US authorities have charged Assange with violating the Espionage Act by conspiring with former US military intelligence analyst Chelsea Manning to leak a trove of classified material in 2010 relating to the wars in Iraq and Afghanistan.

The secret documents were released on WikiLeaks while Assange also collaborated with journalists at prominent news outlets.

His supporters and press freedom groups view him as an investigative reporter who has brought war crimes to light.

In 2010, Sweden announced that its officers were investigating two accusations of sexual assault against Assange, which he denied and said were without merit.

After an international arrest warrant was issued, Assange launched a legal battle against extradition to Sweden.

After that failed, he sought refuge in London’s Ecuadorian embassy in 2012, stating he believed it would eventually lead to an extradition to the US.

Sweden dropped its investigation in 2017.

In April 2019, Assange’s asylum status was revoked, prompting UK police to arrest him for breaching his bail conditions in 2012.

Mexico offers asylum

Mexico’s government is ready to offer political asylum to Julian Assange and supports the decision of a UK judge to deny extradition of the WikiLeaks founder to the US, President Andres Manuel Lopez Obrador says.

“I’m going to ask the foreign minister … to ask the government of the United Kingdom about the possibility of letting Mr Assange be freed and for Mexico to offer political asylum,” Lopez Obrador told a regular news conference.

“Assange is a journalist and deserves a chance, I am in favour of pardoning him,” he said.

“We’ll give him protection.”

Obrador, who called the decision not to extradite Assange a “triumph of justice”, a year ago urged the UK to release him, calling his detention “torture” and saying WikiLeaks documents had showed the world’s “authoritarian” workings.

Obrador, who took office in December 2018, has long railed against ruling elites and rhetorically has sought to break with establishment politics and economics.

-with AAP