Assange extradition could test patience of Australia and US allies, Bob Carr warns

The former Australian foreign minister Bob Carr believes the prison sentence faced by Julian Assange if he were extradited to the US “changes the game” almost as much as a capital punishment charge, and could “test the patience” of its allies including Australia.

Prosecutors in the US on Thursday announced 17 additional charges against the WikiLeaks founder for publishing hundreds of thousands of secret diplomatic cables and files on the wars in Afghanistan and Iraq. Assange faces a maximum sentence of 175 years in prison in the US if convicted of all the charges against him.

The UK government had previously given assurances to Ecuador’s president, Lenín Moreno, that Assange would not face extradition to the US if he could face the death penalty and, similarly, Carr said on Friday that the Morrison government “must oppose” any extradition of an Australian that could lead to capital punishment.

But Carr, the former New South Wales premier who served as foreign minister in the Gillard government, said the size of the potential punishment appeared almost as significant.

Related: New US charges against Julian Assange could spell decades behind bars

“While it appears capital punishment does not apply in this case, the US, by seeking extradition for offences that might attract a 175 years imprisonment, could be testing the tolerance of its allies and partners,” he said. “I think this changes the game almost as much as if capital punishment were the penalty.”

As well as capital punishment, the US-UK extradition treaty also excludes “political offences”. While that definition is not clearly defined, Carr said the charges against Assange could be viewed as “thoroughly political”.

“Sweden and the UK would not allow extradition were the offence one that would attract capital punishment and they also rule out extradition where the crime was said to be ‘political’,” he said. “It could be that convicting someone for life who exposed war crimes and other abuses is seen as thoroughly political.”

Carr said Australia’s foreign minister, Marise Payne, “needs to protect herself from the charge that she’s failed in her duty to protect the life of an Australian citizen”.

“Therefore I would imagine that Dfat [the Department of Foreign Affairs and Trade] will provide her with talking points to conversations with her British, Swedish and indeed American counterparts.

“Not to do so would leave the minister exposed to withering criticism that they did not take all appropriate action that might have mad a difference, mainly before the British court makes a decision.”

Assange, 47, was previously charged with working to hack a Pentagon computer system in a secret indictment that was unveiled soon after his arrest last month at Ecuador’s embassy in London.

He is now serving a 50-week sentence in a UK jail for skipping bail, when he fled to the Ecuadorean embassy in London in 2012.

The latest charges have prompted widespread criticism from press freedom groups because of the consequences both for the first amendment in the US, but also journalists reporting on national security elsewhere.

In Australia, the head of the Media, Entertainment and Arts Alliance, Marcus Strom, said the US government was “trying to set a precedent to criminalise reporting on national security matters”.

Rex Patrick, one of a handful of senators who will likely wield the balance of power in the upper house in the new parliament, called the charges “a grave threat to freedom of the press worldwide” and said the Australian government must be “outspoken” on Assange’s behalf.

“The United States government’s decision to charge Australian citizen and publisher Julian Assange with new espionage offences relating to receiving and publishing classified US government information raises a grave threat to freedom of the press worldwide, and must be viewed so by the Australian government,” he said.

“The Australian government should be active not only in providing consular support to Mr Assange, who is an Australian citizen, but also outspoken in making representations to the British government against allowing Mr Assange to be extradited to the United States on charges that so obviously constitute a grave threat to press freedom.”

The Australian barrister and adviser to Assange Greg Barns said the government should “intervene” on the whistleblower’s behalf, calling for the Payne and the prime minister, Scott Morrison, to raise his case with their US and UK counterparts.

“Australia does have a role to play here and our view is that the Australian government needs to intervene,” he told Guardian Australia.

Barns said the “disproportionate” nature of the sentence Assange faced in the US compared with equivalent charges in Australia, coupled with the free speech implications of the case meant the government should intervene.

“This is not a legal process, it’s a political process and it has ramifications for freedom of speech not just in the US but globally,” he said.

“We know that the Obama administration didn’t bring espionage charges for a very good reason, and that’s because at the end of the day the first amendment and freedom of speech issues overwhelmed it.

“The danger this presents is not only to whistleblowers or journalists in the US, it’s anyone who publishes information the US deems to be classified anywhere in the world. In other words, its the extraterritorial reach of the charges. They represent a direct threat to freedom of speech not just in the US but anywhere in the world.”

Barns said there were clear precedents for the Australian government to lobby on behalf of Australian prisoners overseas.

“What we would say is those messages ought to be communicated to Washington and London and what I can say is Julie Bishop as foreign minister did raise Julian Assange’s case in Washington and London so we would expect Marise Payne but also Scott Morrison to do the same with a view to ending this matter,” he said.

“It’s not as though we’re asking the government to do something unusual – it was a conservative Australian government which brought David Hicks back to Australia.”

In April, when Assange was arrested by police in the UK, Payne said he would “continue to receive the usual consular support from the Australian government”.

Morrison has previously said Assange would receive consular support but would not get “special treatment”.

During a Senate estimates hearing in October, Senator Patrick asked foreign affairs officials what role they were prepared to play in the event Assange was indicted by the US.

At the time, a department official said the government was “not able to interfere in the legal processes of any foreign country, just as we would not welcome interference in the legal processes of this country”.

“Mr Assange has his own independent legal advice and we encourage and have encouraged Mr Assange to use those resources and also the judicial process in the United Kingdom to resolve his circumstances,” the official said.

The official said he was “not aware” of any discussions within the government about the potential for Assange to return to Australia.

“I’m not aware of any discussion about a pathway back other than our firm view that Mr Assange should take an opportunity to undertake due legal process in the United Kingdom, face those charges that he may face when he leaves,” he said.

“We have assurances from the United Kingdom at the highest levels that he will face due legal process in that country.

Related: Indicting a journalist? What the new charges against Julian Assange mean for free speech

“He is entitled to an Australian passport. He is free to travel back to Australia at any time. And it is our view that he is free to leave the Ecuadorian embassy at any time he wishes.”