Assange, 52, has been fighting extradition to the US over espionage charges for obtaining and publishing classified information.

But on Tuesday Australian time, the Queensland-born journalist agreed to plead guilty as part of a deal with US prosecutors, ending his imprisonment in the UK and paving the way to return to Australia.

In a video posted by Wikileaks, Assange is shown boarding a flight out of the UK.

“WikiLeaks published groundbreaking stories of government corruption and human rights abuses, holding the powerful accountable for their actions,” the organisation wrote on X, formerly Twitter.

“As editor-in-chief, Julian paid severely for these principles, and for the people’s right to know.

“As he returns to Australia, we thank all who stood by us, fought for us, and remained utterly committed in the fight for his freedom.

Australia has long called for the US to end its pursuit of Assange, born in Townsville and who studied at the Central Queensland University in Rockhampton.

Prime Minister Anthony Albanese has directly raised the issue with US President Joe Biden and in September, politicians from all sides of Australia’s political spectrum converged on Washington to lobby US decision makers.

Opposition foreign affairs spokesman Simon Birmingham welcomed the decision.

“We have consistently said that the US and UK justice systems should be respected,” he said in a statement.

“We welcome the fact that Mr Assange’s decision to plead guilty will bring this long running saga to an end.”

Nationals Senator Matt Canavan also celebrated.

“Julian Assange will finally be a free man!” he wrote on X.

Nationals MP Barnaby Joyce, who was part of the Washington delegation, said he was encouraged but warned politicians to remain cautious as the legal process was ongoing.

“We’re in the process of a 1500-metre race, we don’t stop and start waving at the crowd on two-and-a-half laps, we wait to the end of the race.”

Assange’s wife Stella was elated.

“Words cannot express our immense gratitude,” she wrote on X.

Bring Julian Assange Home campaigner Antony Loewenstein said Assange’s release was “the best news imaginable”.

“He’s a journalist, he hasn’t hurt a soul, hasn’t hurt anybody, hasn’t killed anybody, hasn’t done any harm to anybody,” he told Sky News.

“I’m absolutely relieved that he’s finally out.”

Greens Senator David Shoebridge said Assange should never have been charged and he looked forward to his return.

“I along with millions of Australians are looking forward to welcoming Julian back home where he belongs with his family and his friends,” he said.

“On this day we again commit to fixing whistleblower laws in Australia and supporting truth telling across the globe.”

Under the US deal, Assange agreed to plead guilty to a single criminal count of conspiring to obtain and disclose classified US national defence documents, according to filings in the US District Court for the Northern Mariana Islands.

He is due to be sentenced at a hearing on the island of Saipan at 9am local time on Wednesday.

It’s unclear exactly where Assange will be at the time of the hearing.

In April at the White House, Mr Biden told reporters he was considering Australia’s request to drop the charges against Assange.

Prosecutors wanted to put Assange on trial for publishing military documents about the war in Afghanistan and Iraq, which authorities said had damaged national security and endangered the lives of US agents.

Assange was arrested in the UK in 2010 on a separate matter and took refuge in Ecuador’s embassy in London. He was taken from the embassy and sent to Belmarsh prison in 2019.