WikiLeaks founder Julian Assange is travelling to his native Australia following his dramatic release from prison after five years of fighting extradition to the United States.

He had to pay half a million US dollars for a chartered flight from Stansted, accompanied by a WikiLeaks lawyer, a representative of the Australian government and a medic to check on his health.

His wife Stella said her relief at his release was coupled with anger that he had spent so long in prison.

She told the PA news agency that she travelled to Australia with the couple’s two young sons Gabriel and Max on Sunday when it became clear that Assange would be freed.

He has reached a plea deal with US authorities which is set to be formalised early on Wednesday, with details expected to be released after that.

He will plead guilty to an Espionage Act charge of obtaining and disclosing information of national importance, with a proposed sentence of time served.

He will return to his home country of Australia after his plea and sentencing, scheduled for Wednesday morning local time in the Mariana Islands, a US commonwealth in the Western Pacific.

Speaking from Australia, Mrs Assange told the PA news agency: “It is hard to believe that Julian has been in prison for so long. It had become normalised. I am grateful to the people who made this possible but I am also angry that it ever came to this.

“Overall I am elated but I cannot believe it is actually happening until I see Julian.”

Mrs Assange said her husband’s release would not have happened without the intervention of Australian Prime Minister Anthony Albanese, who has been increasingly vocal in demands for the United States to drop charges against Assange.

“The public climate has shifted and everyone understands that Julian has been the victim.

“Things are still very sensitive. Julian is paying for the flight so we will launch a fundraising campaign.”

She had a video call with her husband from Sydney, showing him pictures of the Opera House.

She revealed that Assange left Belmarsh in the early hours of Monday and spent several hours at Stansted before his flight left.

In a High Court order, Dame Victoria Sharp and Mr Justice Johnson said Assange left the jurisdiction of England and Wales at 6.36pm on Monday, after the plea agreement was signed on June 19.

The judges added that it was “anticipated that a plea will be entered and accepted on Wednesday June 26 2024, after which the United States have undertaken to withdraw the extradition request”.

The Crown Prosecution Service (CPS) said a bail hearing for Julian Assange was held in private on June 20. This was at Westminster Magistrates’ Court, PA understands.

John Sheehan, head of extradition at the CPS, said: “This has been a highly complex matter involving advising and representing the Swedish and US authorities. In this period, the CPS’s extradition unit has faced and dealt with novel and challenging legal issues. Mr Assange has also utilised all the legal protections available to him.

“This has culminated in facilitating the arrangements necessary to enable Mr Assange to leave the UK legally and safely.”

Simon Crowther, Amnesty International’s legal adviser, said: “We welcome the news that Julian Assange is to be released, as we believe he should never have been imprisoned like this in the first place.

“The fight to protect freedom of expression continues though. The years-long global spectacle of the prosecution of a publisher for revealing alleged war crimes, crimes against humanity and other human rights violations has undoubtedly done historic damage.”

In a statement posted on X, formerly Twitter, just after midnight on Tuesday, the official WikiLeaks account said Assange was released from Belmarsh prison on Monday morning “after having spent 1,901 days there”.

The statement continued: “He… was released at Stansted airport during the afternoon, where he boarded a plane and departed the UK.

“This is the result of a global campaign that spanned grass-roots organisers, press freedom campaigners, legislators and leaders from across the political spectrum, all the way to the United Nations.

“This created the space for a long period of negotiations with the US Department of Justice, leading to a deal that has not yet been formally finalised.”

Video posted to X by WikiLeaks showed Assange, seated and dressed casually in jeans and a shirt, discussing the text on a sheet of paper.

He is then shown walking up steps onto a Vista Jet aircraft.

Speaking about Assange’s release, Australian Prime Minister Anthony Albanese told the nation’s parliament on Tuesday “we want him brought home to Australia”.

He said: “I’ve been very clear as both the Labour leader and opposition, but also as prime minister that – regardless of the views that people have about Mr Assange’s activities – the case has dragged on for too long.

“There is nothing to be gained by his continued incarceration and we want him brought home to Australia.”

Mr Albanese added that Australian diplomatic forces “have engaged and advocated Australia’s interest using all appropriate channels to support a positive outcome”, which he took up early in his role after being elected prime minister in 2022.

He added: “I will have more to say when these legal proceedings have concluded, which I hope will be very soon, and I will report as appropriate at that time.”

A letter to the United States chief judge of the District Court for the Northern Mariana Islands Ramona V Manglona, as seen by PA, also confirmed Assange intends to return to Australia once proceedings conclude.

The WikiLeaks statement also thanked “all who stood by us, fought for us, and remained utterly committed in the fight for his freedom”.

It said: “After more than five years in a 2×3 metre cell, isolated 23 hours a day, he will soon reunite with his wife Stella Assange, and their children, who have only known their father from behind bars.

“WikiLeaks published ground-breaking stories of government corruption and human rights abuses, holding the powerful accountable for their actions. 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. Julian’s freedom is our freedom.”

In a separate post on X, Mrs Assange said: “Julian is free!!!!

“Words cannot express our immense gratitude to YOU – yes YOU, who have all mobilised for years and years to make this come true. THANK YOU. THANK YOU. THANK YOU.”

Assange’s father John Shipton told PA he felt “elated” at hearing the news of his son’s dramatic journey from the UK and that his release had “lifted a huge burden” from his family.

He said recent court hearings in the UK had given him hope that the “tide was turning” in his son’s favour, as well as increasing pressure from the Australian government.

Speaking from Australia, he said he hoped his son will spend time “walking along beaches and listening to birds” in the next few weeks and months.

Assange’s mother, Christine Assange, told Australia’s Sky News that she is “grateful” her son’s ordeal is “finally coming to an end”.

She said: “This shows the importance and power of quiet diplomacy. Many have used my son’s situation to push their own agenda, so I am grateful to those unseen, hardworking people who put Julian’s welfare first.

“The past 14 years have obviously taken a toll on me as a mother, so I wish to thank you in advance for respecting my privacy.”

Assange had been locked in a lengthy legal battle in the UK over his extradition, which saw him enter and live in the Ecuadorean Embassy in London in 2012 before his detention in Belmarsh prison.

In a January 2021 ruling, then-district judge Vanessa Baraitser said Assange should not be sent to the US, citing a real and “oppressive” risk of suicide, while ruling against him on all other issues.

Later that year, US authorities won a High Court bid to overturn this block, paving the way towards Assange’s extradition.

Assange was due to bring his own challenge to the High Court in London in early July after he was recently given the go-ahead to challenge the original judge’s dismissal of parts of his case.

Assange has been in custody at HMP Belmarsh for more than five years, fighting his lengthy legal battle against extradition to the United States.