Jade Goody’s original claim to fame was that she was unable to locate “East Angular” correctly but the reality show contestant has moved on from that to causing an international diplomatic incident, embarrassing Gordon Brown, and causing heartache for Channel 4 at the moment when the broadcaster is trying to get its hands on more money.

Until Tuesday, Celebrity Big Brother was sliding into D-list obscurity, averaging 1.7 million viewers a night, until an arrant display of prejudice — and arguably racism — pushed the figures up to 4.5 million amid a deluge of complaints.

In some quarters the response has been predictable: calls for Jade and her bullying allies to be thrown out of the house, perhaps charged by police; for Channel 4 and the show’s producers, Endemol, to intervene directly; for Ofcom to have the power to halt transmission; and calls to reopen the debate about the broadcaster’s ownership.

Yet, on the evidence of what has been transmitted to our screens so far, all this is simply excitable, heat-of-the-moment stuff. Racism would achieve a significant victory if it resulted in an instant policy fix.

It says a lot about Britain today that a violent, non-fatal racist attack would generate only a few paragraphs of news coverage. But an on-screen, non-violent row, in which race is a dimension, gets the whole nation talking, and the media and some politicans into a frenzy.

That, though, is the curious power of Big Brother — a format that means little or nothing to the over-40s, but in the post-modern, war-is-only-on-the-news era, it is able to animate millions. Amid all the talk of the death of broadcast television, and the shift to advertising online, there is no clearer reminder of the incredible power of the small screen.

Big Brother was devised as an unscripted social experiment; the original debate when it was created was whether there would be sex on screen, although the British have proved far too sensible for that. Instead, housemates have taken the programme in other unexpected directions, and there is no reason why everybody should like what they see (go and watch the BBC for television that tries to offend as few people as possible).

What has happened to Shilpa Shetty, a genuine megastar, in the past few days has been deeply uncomfortable — but also compelling — viewing. It will divide opinion, offend many, and it will also get people thinking. To believe that Britain in 2007 is a uniformly nice place is to display staggering naïvety; if it takes reality television to remind us of that, so be it.

There are limits, of course, but there is no need for intervention in the programme at the first whiff of controversy. Intervention should be required only when the law (in this case against inciting racial hatred) has clearly been broken. Channel 4 is just about right when it says that “no overt racism” has occurred, although that does not absolve the broadcaster of a duty to warn housemates if that does occur.

The broadcaster and producer must be sure that no attempt was made to stoke a race row in the selection of contestants: Celebrity Big Brother thrives on humiliation and conflict. That is bearable if unplanned, but when you find that one housemate (Donny Tourette) had an affair with another’s wife (Leo Sayer), there has to be a worry that Endemol is pushing the search for conflict too hard.

For Channel 4, meanwhile, the row is double-edged. Such a naked display of audience-winning commercialism does nothing at all to help the broadcaster to advance its pleas of poverty in Whitehall. Profits are down by more than two thirds to £20 million in 2006, but that is also because of digital investment in E4, More4 and online, and not just the weak advertising market.

As the Big Brother brouhaha shows, Channel 4 is strong and vibrant enough to look after itself without any special help in kind from the authorities, which Mr Brown may be reluctant to endorse after his prime ministerial trip to India has been blown off course.

However, it is a lot to argue that from one row about one show that it is time to privatise Channel 4. The point about the broadcaster is that it was set up to be innovative, and transmit programmes that were too edgy for the BBC and ITV, and Big Brother is exactly that.

Channel 4’s public service contribution is often exaggerated (a one-hour news programme was good to have in the 1980s, but now there are several 24-hour news channels), but its blend of highbrow and trash TV makes it unique. Flogging it off, almost certainly into the hands of a foreign owner, would undoubtedly lead to a blander channel aimed solely at profit-making, unless it was established as an independent trust.

In an age where an e-mail petition and a few front pages lead to calls that Something Must Be Done, the hardest thing to do is to accept, and even celebrate, what Big Brother is all about: a fairground mirror of British society. The reflection is strange, and unexpected perhaps, but it is a reflection nevertheless.

dan.sabbagh@thetimes.co.uk

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