Capital punishment
Illustration depicting capital punishment for treason in 1535 Getty Images

On a dank February morning in 1663, the printer John Twyn was dragged through the streets of London to his place of execution at Tyburn (now Marble Arch). Before a jeering crowd, he was given a few moments to say his final prayers.

Then a rope was forced round his neck and he was pushed off the ladder to twist and kick and choke until nearly dead. He was cut down and disembowelled while still alive. His intestines were ripped out and burned before his dying eyes.

In a final act of butchery his head was cut off, his remains hacked to pieces, his head, arms and legs nailed to the city gates as a warning to others. The barbarity of hanging, drawing and quartering was of course a medieval invention, designed to terrify anyone tempted to commit high treason.

But the unfortunate Twyn was no traitor. His "crime" − if such it can be called − was to print an anonymously-written pamphlet suggesting that King Charles ll might be accountable to his subjects.

A perfectly legitimate point of view? Sure. But at a time when common folk were expected to know their place, free journalism of the kind represented by Twyn was regarded with horror. To the great and the good of the 17th century, the spread of uncontrolled pamphlets and newsletters was a menace. In the words of the official censor, Sir Robert L'Estrange, freedom of information "makes the Multitude too Familiar with the Actions and Counsels of their Superiors…"

Well, we've come an awful long way in the last 350 years, haven't we? Supposedly, anyway. Yes, in our more civilised society we treasure the right to say what we think. We're proud of the fact that our newspapers are free to report and editorialise without fear. We pity those sorry countries where censors hold sway and the public's right to know doesn't exist. We think such dictatorial excess couldn't possibly happen here.

But aren't we deluding ourselves? We may no longer send writers or printers to the gallows for speaking the truth about power, but there are other ways of coercing newspapers into silence, as David Cameron, Ed Miliband and Nick Clegg have shown.

Yes, the former leaders of all three of our mainstream political parties agreed to push a new law through Parliament that would impose harsher controls on the British Press than exist in any other Western democracy. If the legislation is fully implemented – as it could be in a matter of week − there will probably never again be newspaper exposes of the kind that have shone so much light into so much darkness.

Sexual grooming by predatory gangs in Rotherham? In future, no paper would dare report it. The outrageous story of MPs' expenses? Ditto. Corruption at the heart of world football? The great Olympics drugs scandal? The exposure of greedy businessmen ripping off the NHS with overpriced medicines? You'd never hear a word about any of them. Messrs Cameron, Miliband and Clegg would have seen to that.

So how? Why, by a cunning little device known as Section 40 of the Crime and Courts Act, 2013. Under this legislation, which is now out for public consultation, any publication that dared to tell the truth about corrupt officials, MPs with their fingers in the till, crooked businessmen or anyone else who happens to be rich and powerful would face utter ruin.

And it won't matter if every word those newspapers have printed is absolutely true. Nor will it matter if the journalists involved are shown to have performed a valuable public service. Any villain exposed by the Press could simply launch a libel action secure in the knowledge that the paper involved would be forced to pay all the legal costs – probably running into millions − even if it won the case hands down. The loser wouldn't have to pay a penny.

Newspapers have only one way out of this dilemma. If they sign up to the Government-approved regulator Impress – an outfit largely financed by Max Mosley, an embittered victim of a tabloid sex sting − they could avoid all these penalties. But no self-respecting paper will submit to a system that opens the door to state control.

Section 40, in short, is not only akin to blackmail. It's also the only legislation in the history of this country that deliberately sets out to punish the truth-teller. It's a wrongdoers' charter, a law that benefits the guilty, an affront to natural justice and an insult to democracy. So how did the politicians manage to concoct such an unholy mess?

The answer goes back to the phone-hacking scandal and the subsequent Leveson inquiry into the Press, events that sparked understandable public outrage at the appalling behaviour of some newspapers. And some politicians – still smarting over the revelations about MPs' expenses – were only too happy to seize the opportunity for revenge.

Cameron, Miliband and Clegg were certainly responding to that mood when they met representatives of the pressure group Hacked Off to agree Draconian new controls on the Press, including Section 40. But haven't times changed since then? The News of the World has been closed because of the hacking scandal. The Press has set up a powerful new system of self-regulation. Hugely expensive court cases against a succession of journalists have ended in acquittals.

It should be time for a new beginning, both for politicians and the Press. But the threat of censorship still hangs over the newspaper industry. Public consultation on Section 40 ends next week, on 10 January. After that? Nobody knows. There are many MPs and peers who are just aching to see Section 40 enforced and the Press taken down a peg or two.

And if that happens? Then newspapers would have some stark choices. They could save themselves by concentrating on football, fashion and society gossip, abandoning investigative journalism altogether. They could sign up to Impress, opening the door to political control. Or they could fight against a law that shames the politicians who voted for it.

One thing is clear: our political masters haven't changed all that much in the last 350 years. Like that official censor in the 17th century, don't many of them still hate the Press because "it makes the Multitude too Familiar with the Actions and Counsels of their Superiors"?

Michael Toner is a former Fleet Street political editor and co-author of a series of Bluffers' Guides on Europe.