Julian Assange is in custody at London’s Belmarsh prison as he battles a US attempt to extradite him to face charges in connection with the publication of leaked documents. (AP)

Across the political spectrum, Australian federal MPs have asked US attorney general Merrick Garland to drop efforts to extradite Julian Assange from the UK.

The 48 senators and representatives, 13 of whom are from the ruling Labor party, warned that the hunt for the WikiLeaks founder "set a dangerous precedent" for press freedom and would harm the US reputation.

Assange, an Australian citizen, is still detained in Belmarsh prison in London as he resists a US request to extradite him to stand trial on charges related to the release of tens of thousands of leaked diplomatic papers about the atrocities of US wars in Afghanistan and Iraq.

The Labor, Coalition, Greens, and crossbench MPs pleaded with Garland to "drop the extradition proceedings and allow Mr. Assange to return home" in an open letter that was published on Tuesday.

“If the extradition request is approved, Australians will witness the deportation of one of our citizens from one Aukus partner to another – our closest strategic ally – with Mr Assange facing the prospect of spending the rest of his life in prison,” the letter said.

“This would set a dangerous precedent for all global citizens, journalists, publishers, media organizations and the freedom of the press. It would also be needlessly damaging for the US as a world leader on freedom of expression and the rule of law,” it added.

The letter acknowledged that the allegations - which include 17 counts under the Espionage Act and one count under the Computer Fraud and Abuse Act - pertained to Assange's acts "as a journalist and publisher" in publishing information "with evidence of war crimes, corruption, and human rights abuses."

The MPs and senators compared Assange's continuous persecution to that of Chelsea Manning, a former US Army intelligence analyst who was freed in 2017 after Barack Obama commuted her 35-year military prison sentence for disclosing the information.

The letter went on to say that Assange – who initially took refuge in the Ecuadorian embassy in London – “has been effectively incarcerated for well over a decade in one form or another, yet the person who leaked classified information had their sentence commuted and has been able to participate in American society since 2017."

The letter was sent by independent MP Andrew Wilkie, who also serves as co-chair of the Parliamentary Friends of Julian Assange Group. It falls on the same day as Assange's fourth anniversary of being imprisoned in Belmarsh.

According to Wilkie, the 48 federal lawmakers from Australia were representing millions of constituents by working "in concert with similar letters from parliamentarians from around the world."

“This is no small matter and must not be dismissed,” Wilkie said. “Nor should it be ignored that the outpouring of political concern spans the political spectrum and is based on a diverse range of reasons.”

On his account, Assange’s father, John Shipton, made a heartwrenching remark, revealing that said his son had been living under “a pall of shame and disgrace."

Shipton said the ruling by the new Australian high commissioner to the UK, Stephen Smith, to visit Belmarsh prison last week marked “the beginning of the end of this bleak, severe frost on truth and destruction of Julian Assange."

Julian Assange's lawyer recently cited suicide as a possible outcome if the Australian is extradited to the #US on his espionage charges.
Here's a timeline of some key dates from Assange’s life.#JulianAssange #FreeAssange pic.twitter.com/FTSGibxwQO
— Al Mayadeen English (@MayadeenEnglish) October 30, 2021

Greg Barns SC, a legal advisor to the Assange campaign, warned the US attempt to prosecute Assange was “dangerous” because it meant “any journalist or publisher anywhere in the world could face extradition to the US for exposing material Washington doesn’t want you to know about."

The 13 Labor MPs to ink Tuesday’s letter were Michelle Ananda-Rajah, Mike Freelander, Julian Hill, Peter Khalil, Tania Lawrence, Zaneta Mascarenhas, Brian Mitchell, Alicia Payne, Graham Perrett, Susan Templeman, Maria Vamvakinou, Josh Wilson and Tony Zappia.

It is worth noting that the former deputy Prime Minister Barnaby Joyce and the member of parliament for Bass, Bridget Archer, were the most prominent Coalition signatories.