WikiLeaks founder and Australian citizen Julian Assange has appealed to a British court to block his extradition to the United States, where he faces criminal charges and possible death. 

Mr Assange, a 51-year-old man from Townsville in North Queensland, is wanted by US authorities on 18 counts including spying in relation to his whistleblowing outfit WikiLeaks' release of vast troves of confidential US military records and diplomatic cables. He faces up to 175 years in prison.

The revelations Mr Assange made through WikiLeaks exposed details about civilian deaths, friendly-fire casualties, US air raids, al-Qaeda’s role in Afghanistan, information on Guantanamo Bay prison detainees, and nations providing support to Afghan leaders and the Taliban. The information has been highly embarrassing to the US in particular, but is considered by many to be in the public interest.

UK Home Secretary Priti Patel recently approved his extradition to the US, saying UK courts had ruled his extradition is not incompatible with his human rights.

But Mr Assange's legal team has lodged an appeal against that decision at the High Court, his brother Gabriel Shipton says.

“We also urge the Australian government to intervene immediately in the case to end this nightmare,” Mr Shipton told Reuters.

Independent MP Andrew Wilkie recently declared that the time for “whispers and secret handshakes” to free Julian Assange is over.

He has called on the Albanese government to take “strong action” to secure the WikiLeaks founder’s freedom.

“Julian Assange has been incarcerated for near on a decade both in the Ecuadorean embassy and must be about three years now in Belmarsh prison in London,” Mr Wilkie told Sky News.

“I, and I think a lot of people, have given the new government time to resolve this.

“But there we were last Friday and the British home secretary actually signed off the extradition of Julian Assange to the US.”

Mr Albanese has suggested any diplomatic representations to help the imprisoned WikiLeaks founder would be made behind closed doors.

“I have made clear on what my position is publicly. I made it clear last year,” Mr Albanese said.

“I stand by my comments that I made then.

“I make this point as well, there are some people who think that if you put things in capital letters on Twitter and put an exclamation mark that somehow makes it more important. It doesn’t.

“I intend to lead a government that engages diplomatically and appropriately with our partners.”

Immigration Minister Andrew Giles says the Albanese government believes “enough is enough” when it comes to Mr Assange’s treatment.

“I’m very confident in the work happening behind the scenes by Foreign Minister Penny Wong,” he told ABC Radio.

Senator Wong has issued a joint statement with Attorney-General Mark Dreyfus saying the Department of Foreign Affairs and Trade is providing consular assistance.

“The Australian government has been clear in our view that Mr Assange’s case has dragged on for too long and that it should be brought to a close,” they said.

Strong questions remain about Mr Assange’s physical and mental health.