Later this month, a journalist will appear at a London court hearing in which he faces being extradited to the United States to spend the rest of his life in prison. The 18 charges against him are the direct result of his having revealed a host of secrets, many of them related to the US prosecution of wars in Iraq and Afghanistan.

They included the “collateral murder” video which showed a US helicopter crew shooting 18 people in Baghdad in 2007, including two Reuters war correspondents, Namir Noor-Eldeen and Saeed Chmagh. Among the files were thousands of military dispatches and diplomatic cables that enabled people in scores of countries to perceive the relationships between their governments and the US. They also showed the way in which American diplomats sought to gather personal information about two UN secretary generals.

Unsurprisingly, the revelations were gratefully published and broadcast by newspapers and media outlets across the world. “Scoop” is far too mundane a term to describe the staggering range of disclosures. By any journalistic standard, it was a breathtaking piece of reporting, which earned the journalist more than a dozen awards.

Human rights report to oppose extradition of Julian Assange to US Read more

So, you might think that this press freedom hero, now incarcerated in Belmarsh prison, would be enjoying supportive banner headlines in Britain’s newspapers ahead of his case. Thus far, however, coverage of his plight has been muted. Why?

The answer is that our hero is none other than Julian Assange, the man who skipped bail to avoid an extradition order to Sweden over an allegation of rape, which he denies, and took shelter in the Ecuadorian embassy for seven years until police were allowed to enter and arrest him last April. Many falsehoods were told about Assange during his time inside the embassy, including bizarre stories about his smearing faeces on the walls, ruining the floors by skateboarding and torturing a cat.

These tales, and many more like them, have contributed to the largely negative perception of Assange and the website he helped to found, WikiLeaks. Some of it was orchestrated by the US government following the 2010 release of the collateral murder footage and the arrest of the whistleblower, Chelsea Manning, who was responsible for leaking the material.

In Britain, Assange’s reputation suffered from his falling-out with several people who had admired his work, including at the Guardian, which had published stories based on the WikiLeaks documents. As the paper’s then editor, Alan Rusbridger, noted: “The relationship with Assange was fraught … I found him mercurial, untrustworthy and dislikable: he wasn’t keen on me, either.”

I met Assange only once, when he came to a talk at City, University of London, and was less than impressed by his grandstanding entrance and performance. But, like Rusbridger, I think personal feelings about Assange’s character have to be put to one side. The far-reaching implications of this case against him are hugely significant for the future of the journalistic trade.

Assange has been charged with 17 counts under the US Espionage Act of 1917, each of which carries a 10-year sentence, and one of “conspiracy to commit computer intrusion”, which carries a five-year maximum sentence. He could therefore be jailed for 175 years. These offences may relate specifically to one man’s activities but, should they succeed, they would set a terrible precedent. The aim is to prevent whistleblowers from telling the truth and journalists from giving them a platform.

The far-reaching implications of this case are hugely significant for the future of the journalistic trade

What Manning and Assange did cannot be construed as espionage. They were casting light on the US government’s murky secrets and, in the case of the collateral murder video, the lengths it was prepared to go in order to cover up a massacre. That’s journalism, pure and simple.

It means that press freedom is at risk, and we should not be persuaded to pass by on the other side of the road just because we don’t like the guy involved. I am delighted that national editors who responded to my emailed question last week about their views seem to feel the same way.

The Daily Telegraph’s Chris Evans says that although he is “heavily conflicted” about Assange, he is alarmed by “the implications for journalism” should he be extradited. The Daily Express editor, Gary Jones, is “reluctant to describe Mr Assange as a journalist”, but thinks he “lifted the lid on very serious abuses of power and corruption” and believes “the British government should stop his extradition”.

The Guardian’s editor, Katharine Viner, was unequivocal: “State power should never be used to suppress the actions of whistleblowers and investigative journalists pursuing stories that are clearly in the public interest. The US extradition case against Julian Assange is a troubling attack on press freedom and the public’s right to know.”

Two editors, speaking off the record, were reluctant to take a definitive position before they have more detailed knowledge about the case. Their main concern was about the possibility that the release of files by WikiLeaks may have endangered people’s lives. But I cannot find any evidence that anyone was arrested, let alone tortured or killed, as a result.

I would like to see Britain’s editors – national, regional and local – get to grips with this case in advance of the first hearing, due to start on 24 February, and then to issue a considered statement, probably through the Society of Editors, opposing Assange’s extradition. At the same time, they need to alert their readers and pressure politicians, in order to highlight the injustice of this prosecution and why it is so important. They don’t have to change their minds about the man’s character. They just need to stick to the principle.

I don’t think it’s too far-fetched to see a parallel between the Assange case and the Dreyfus affair in the 1890s, in which a Jewish artillery captain in the French army was falsely convicted of spying. At least Dreyfus was eventually released from Devil’s Island. If the US gets its hands on Assange, there will be precious little hope of escape.

It is sobering to note that Manning, whose original sentence was commuted, is now in jail because she refuses to testify against Assange. She, too, is a hero of press freedom.