Peter York on ads: Trinny and Susannah take us all for mugs

Whenever Margaret Thatcher appeared on TV in the 1980s, some people thought she was common and frightful but a lot more either thought she was dead posh or didn't understand the question.

Her frightfulness was paramount to people like Mary Warnock. Lady Warnock, academic and committee woman, hated Mrs Thatcher's voice, use of language and clothes; everything about the Leaderene obviously made her shudder. Lots of Oxbridgey upper-middly media village people felt the same. Mrs Thatcher represented precisely that sort of triumphalist provincial lower middleness, re-potted in the Home Counties, that they hated (many of them had a distinctly soft spot for one-nation toff Tories).

But vocal as it was, the constituency that recognised precisely what Mrs Thatcher represented in the old social spectrum - her degree, so to speak - and cared was pretty small: a few hundred thousand people tops. For most people Mrs Thatcher was the essence of upper classness for the good reason that she was obviously Top Lady Dog: she was powerful, rich, smartly got up, hyper-educated - two degrees Margaret - and "poshly" spoken in an actressy elocuted way. In the Marxist sense that was quite upper class enough to be going along with, even if the design detailing did offend the sensitive.

Audience class perceptions are still an issue for female presenters and performers. The Dinner Party Inspectors had two posh-talking women - Meredith Etherington-Smith and Victoria Mather - standing in judgement on modest people's entertaining at the other end of some TV closed circuitry. The format was deeply uncomfortable even though Meredith and Victoria were stretching every diplomatic sinew to sound unclassist. It was the remote- control element and the unspoken idea of absolute (ie upper- middle) standards that made it such hard going.

But Trinny and Susannah has really worked. Re-commissioned all over the place. Bucketloads of books. Trinny and Susannah are now unlikely all-purpose TV celebrities, part of mainstream Gossip World. It could've been grim; two smart girls - we'll come back to exactly how smart for the socially prurient - commenting on the faces, figures and clothes of ordinary women. Women who'd had children. Women without private education or healthcare or access to the metropolitan finishing school of nice central London shops in areas where the teeniest house costs at least a million. Fat women like Jo Brand. People from an out-there world, completely different from Trinny and Susannah's own. Wouldn't you have thought it'd be completely obvious to the audience just where the girls came from - and wouldn't they be resented for it?

It didn't matter that much, as it turned out. The magazine profiles picked up on their smart private schools, Susannah's Norman family and royal dating history (David Linley) but the format saved them. They were enthusiastic and jokey and they delivered, ie they worked with their cases, they were pioneers in the transformation business, and they came bearing gifts. And they put themselves about. They were everywhere, on every daytime TV show, in every magazine. And, especially, on Friday Night with Jonathan Ross.

There, on BBC1's key Friday night talkshow, a pillar of the schedule - I saw it live, why should I lie to you - the whole civilised world moved on a notch as Jonathan cupped Susannah's breast and she groped him. You'd never have found Parkinson doing that kind of thing with Gloria Swanson. What it really showed was quite how professional and determined Trinny and Susannah were. They really wanted to become a popular brand.

And now they're doing Nescafé. For a second season. Obviously the research must be saying they're aspirational, for all the right reasons. The commercial's all about waking up to a new you. Sorted, Stylish. On top of the world. And there's some sort of contest that could deliver a £10,000 makeover (five times what the BBC budgets for each victim). There's a church hall full of clothes rails on standby for your new wardrobe.

All this involves Trinny and Susannah mugging for the camera in a series of stills - a black and white "Deco" number, a sofa scene on top of a globe and so on - as if they've spent the last 20 years in Emmerdale rather than SW3 and W11. And if they can do it, little girls please note, any ambitious Sloane can.

Peter@sru.co.uk