It is a blunt repudiation of the Mail 's highly personal and sometimes vindictive campaign against 39-year-old Airey. It reminds us once again that the moral majoritarians who control the paper, and those who identify with them, have less grip upon the heartlands of Britain than they like to think.

Just four months ago, the Mail unleashed a campaign of vilification against Channel 5 for broadcasting Naked Jungle , a gameshow hosted by middle-aged presenter Keith Chegwin with no clothes on. Billed cheekily by Airey as an 'exploration of naturism', the programme was remarkable more for the startling slightness of Chegwin's member than any sauciness from the contestants, who also undressed.

The Mail 's blitzkrieg on the show monickered the broadcasters Channel Filth. But six weeks later the Broadcasting Standards Commission conceded that they had received just seven complaints from members of the public. 'It just did not appear to have upset people and generated a tiny response,' said then BSC chairman Lord Holme.

If only Channel 5's detractors could see it, it was a classic demonstration of the marketing nous that has made the station a success. After its shaky launch in the spring of 1997 when half its new viewers saw screens of white snow, it now reaches 84 per cent of British house holds, and looks set to challenge Channel 4's market share.

'We never quite understand why people happily make all the fuss, but we're very grateful,' said a senior source at the station's chic, but modest, central London head office. 'All we have to do is lob a gentle firecracker. The tabloid newspapers go bonkers. Hardly anything ever gets put in a written press release, so no one can say we misled them. And we get publicity we just couldn't buy. Millions tune in to see our so-called pornography. If 5 per cent of them stay behind for some other programme we're laughing all the way to the bank.'

Airey gave a personal demonstration of exactly this tactic when she appeared on Question Time in March this year. Innocently observing that her station's celebrated 'adult output' was being broadcast at exactly the same time as the BBC1 programme, she caused two million viewers to switch over.

But what BBC1's disloyal audience would have seen is hardly pornography at all. It is the gentle smut that has been available on adult cable channels across Europe and America for years. If anyone at Channel 5 sits glued to the screen previewing its bought-in late night films, they are extremely unlikely to go blind before its soft-focus footage of boobies and bottoms.

It exemplifies the channel under Airey and her team. The ethos extends not just to late-night films, but to gentle middlebrow broadcasting. Daytime sofa chat hosted by Gloria Hunniford, the competition Fort Boyard fronted by Melinda Messenger and her famous embonpoint , and, of course, Chegwin. The five nights-a-week soap Family Affairs - which had its own Marchioness-style disaster - attracts three million viewers a week.

Channel 5's high water mark so far was BBC and ITV's notorious 'Black Wednesday' on 8 September 1999. Screening England's crucial Euro 2000 qualifier against Poland in Warsaw, the station achieved an audience of 5.6 million.

Current audience share, touching 6 per cent of total TV viewing after just four years on air, demonstrates that many mid-market viewers are rather more astute than Britain's legion of snooty TV critics.

While it remains painfully obvious that most Channel 5 programmes are low budget, TV consumers have noticed that this makes them no different from much of the output now also shown on ITV, Channel 4 and BBC1.

Last Sunday, with the benefit of the blockbuster film Mrs Doubtfire , audience share rose to 9.2 per cent. That is where Airey comes in. Her predecessor David Elstein, edged out last week with a £4 million share option sweetener, was committed to the 'films, football and fucking' agenda once attributed to Airey herself.

However, a colleague of Airey's explained yesterday: 'Dawn does believe that you can grow the entire audience. Some of that will come down to budget and programme quality, but there is a recognition that lifestyle shows and light, but not pretentious, documentaries have a role to play in building audience profile.

'You don't always have to have the highest audience to guarantee the highest ad yields if you start picking up ABC1s, even when they're promiscuous viewers. Dawn knows that Channel 5 has no constituency which sits down and turns it on automatically, a sort of lethargy which still benefits the BBC and ITV. We have to win them over almost every time. She wants C5 to become more sticky, so people hang around.'

The channel has already launched a series of innocent 'smily' adverts to emphasise its general appeal to family audiences and the late-night boobies are not quite as prevalent as they were. However, there is still likely to be 'creative tension' with Richard Eyre, the devoutly Christian director of strategy for RTL, Channel 5's main shareholder. Eyre, once improbably reported to speak in tongues at a south London Baptist church, insists: 'I would never interfere in programme content on the basis of my personal beliefs.'

Airey's determination is not in doubt. Anyone who has observed her in the gym - redfaced and awash with sweat - will gather that she is a woman who takes almost everything very seriously. Indeed.

She has supreme self-belief. Last year, she trained at Harvard Business School while continuing to run her fledgling channel. Her personal critics have often apparently been motivated by the unpleasant envy habitual when a woman in Britain does well -she must be unbalanced, or sex-starved or, as novelist Will Self chose to hint in a newspaper interview, lesbian.

But Airey gives the impression of appearing not to care. Her matey bonhomie, which makes Mo Mowlam look restrained, is widely admired. And her Cambridge background, just like her predecessor's double-first, is kept well-disguised. What you see, her friends insist, is what you get. Nobody who has studied her previous form - links with Drop The Dead Donkey , Don't Forget Your Toothbrush and The Big Breakfast - can be under any illusion as to the sort of broadcasting she champions. She will also seek to use an increased budget to boost sports coverage.

A BBC source has suggested that it might have been an approach from Greg Dyke - a firm admirer - that precipitated C5's decision to promote Airey. But in future she will look over-qualified to be a mere programme controller. The chief executive's job at a merged ITV, expected within the next three years, almost certainly beckons.

And while the critics continue to carp at Channel 5, it will still be less from censoriousness than old-fashioned snobbishness. Paul Dacre might be disgusted by its 'Carry On Don't Lose Your Bra' public persona, tempered by a dark touch of Joe Orton - this autumn's scheduling highlights include a weekly post-mortem show - and promoted with the irreverence of St Trinians mischiefmakers. But it all touches a seam in the British psyche. Under Airey, this knowing televisual Bacchanalia is unlikely to fizzle out.