If a state regulator told newspaper journalists, authors, playwrights, artists or the general public that they must show "due impartiality", I would say it was attacking basic freedoms. It is not up to the government to dictate what can and cannot be said. The public can listen to the competing voices in the marketplace of ideas and make up its own mind. The old justification for imposing unique controls on radio and television was that space on the airwaves was scarce, and media companies could not squat on it and impose the partisan views of their owners or presenters. The days of "spectrum scarcity" went years ago, however. Satellite television allows hundreds of stations to broadcast, while the web has made the notion of a separate broadcasting sphere absurd. My newspaper broadcasts films and podcasts on its website. The BBC publishes a taxpayer-funded online newspaper. The old divisions make no sense, and you can feel the pressure on the rules that govern them building. The BBC's John Simpson, whose opinion of himself can be gauged by his title of "World Affairs Editor", said he wished he could imitate Snow. Channel 4's managers look as if they want to boost their flagging rating by creating a Fox News of the Left.

But although I cannot defend regulation on grounds of pure principle, I can do so on grounds of the public interest. We do not say, for instance, that teachers are free to teach what they want, as the reaction to Islamist propagandising in Birmingham schools shows. They must meet basic standards or be thrown out. Parents can teach their children what they will at home, but school is a protected space.

The celebrities notwithstanding, most broadcast journalists feel that the law should protect broadcast news as carefully. They do not want to be partisans. Like civil servants and judges, they do not feel that the demand that they leave their political beliefs at the workplace door diminishes them. Indeed they are proud of their ability to separate the private from the public. The journalists other journalists listen to during a Middle East crisis are Lindsey Hilsum of Channel 4, Lyse Doucet of the BBC and Peter Beaumont of the Guardian because we know that they are fanatical about getting a story right. They will never be famous, but they matter to our culture more than celebrity presenters can ever do.

It does not strike me as oppressive that there should be a small corner in the marketplace of ideas where people can go — if they wish — for impartial and accurate journalism. I do not see why we should close it down just because Jon Snow wants to wave his willy at anyone who will look.