CAMPAIGNERS warned of long-lasting damage to global media freedom as Julian Assange’s case returns to court tomorrow.

After years of legal limbo, the High Court in London is due to give a final decision on whether the WikiLeaks founder should be extradited to the United States.

Mr Assange, who published evidence of war crimes committed by the US, is wanted by US authorities on 18 counts over the release of hundreds of thousands of classified documents.

If extradited and convicted in the US, Mr Assange could face a prison term of 175 years under the 1917 Espionage Act, initially used to prosecute spies during World War I.

Protesters supporting Mr Assange are due to rally outside the Royal Courts of Justice tomorrow morning.

They are expected to be joined by Mr Assange’s wife Stella, former Labour leader Jeremy Corbyn and former ambassador and activist Craig Murray.

In March, the court ruled that the US must provide “satisfactory assurances” that Mr Assange would not face the death penalty if he faced trial for spying.

The ruling said the US must also provide assurances that he will not face prejudice “by reason of his nationality” and that the Australian-born journalist be given the same First Amendment rights as US citizens.

Last month, judges confirmed that the US had provided the court with such assurances.

Ms Assange called the diplomatic note “blatant weasel words.”

“[It] does nothing to relieve our family’s extreme distress about his future — his grim expectation of spending the rest of his life in isolation in a US prison for publishing award-winning journalism,” she said. 

Justice Jeremy Johnson, who has previously represented Britain’s Secret Intelligence Service and the Ministry of Defence, is one of two judges who will rule tomorrow on whether they are satisfied with the assurances.

If they are not, Mr Assange will have more opportunities to argue his case for a full appeal before the courts.

But if they are, Mr Assange has only one option left: to appeal to the European Court of Human Rights. He could be on a plane to the US  within 24 hours, his lawyers say.

Amnesty International’s legal adviser Simon Crowther will attend tomorrow’s ruling as a legal observer.

He warned of “the risk that he [Mr Assange] would be subjected to human rights violations and the long-lasting damage that would be done to global media freedom.”

He said: “The authorities in the US seem hell-bent on making an example of Assange for exposing their alleged war crimes, rather than upholding the values of freedom of expression.

“Receiving sensitive government information from outside sources and publishing it in the public interest is not a crime. 

“These are fundamental activities to the work of journalists and publishers. 

“The public has an absolute right to know if their government is breaking international law.”

John Rees, national officer of the Stop the War Coalition, who will chair the protest outside court tomorrow, also warned of the grave impact of a ruling against Mr Assange.

He said: “It sends the message that the United States can treat any journalist of any nationality in any country as a spy.  

“It redefines journalism as espionage and that’s a very profound threat. 

He added: “It greenlights any country to make the same claims.”

Mr Assange is being held in Belmarsh prison, where he has been for five years after being removed from the Ecuadorian embassy where he was given political asylum for nearly seven years.

Last Thursday, MPs wrote a letter to the chairman of the justice select committee calling for an inquiry into the role of the Crown Prosecution Service.

Reports have surfaced that the CPS may have advised Swedish prosecutors against Mr Assange’s questioning in London.

This would have excluded the only legal strategy which could have brought the Swedish case against Mr Assange — for a “preliminary investigation” into accusations of sexual offences allegedly made in August 2010 — to a quick resolution, Italian newspaper il Fatto Quotidiano reported.

“The evidence that has come to light opens the CPS to allegations that it misjudged, or possibly overstepped, its role when advising the Swedish authorities on the extradition of Mr Assange to Sweden” the MPs’ letter reads.

“This leads to questions about the motive behind such actions, including whether the CPS was influenced by another extradition request or aimed to facilitate Mr Assange’s subsequent extradition to the United States.”

The letter was signed by Labour MP John McDonnell, Conservative MP David Davis, Green MP Caroline Lucas and former Labour leader Jeremy Corbyn.