Harriet Walker: Sorry Valérie Trierweiler, you are cast as the femme fatale

There she stands, gloatingly triumphant, upper-leg seam on her tan tights brazenly displayed, the hussy

English women have long been scared of their French counterparts. If not scared, then suspicious. And if not suspicious, then (go on, admit it) just a tiny bit jealous. They're well put together; they're immaculately chic; they're rail-thin despite breakfasting on croissants and Dauphinoise potatoes. How on earth do they manage it?

Well, they dress up because they're after your husband, and they burn off all those calories with their evil scheming, if we're to believe the Daily Mail's Samantha Brick on the matter. Yes, she's back – and she's got it in for France's new First Lady, the very figurehead of witchy Gallic wiles, according to Brick, who is, of course, renowned for being the woman who thinks she's more beautiful than anyone else she's ever met.

"I have lived in France for four years," Brick wrote this week, "and there are few who have a better insight into the sinister machinations of a Frenchwoman's mind than I do."

They are predatory and promiscuous, hostile and ruthless – and they don't like other women, Brick cautions us. She, of course, would know plenty about that. But even the BBC has stooped to it, too, a reporter referring earlier in the week to Valérie Trierweiler's having "stolen" François Hollande from his wife, the former Presidential candidate Ségolène Royal. As I recall, even Heat stopped using that particularly loaded verb when referring to Angelina Jolie and Brad Pitt, for instance, about five years ago.

As a journalist and curtain-twitcher, I appreciate the succulence of this particular backstory; what goes on upstairs from, and next door to, the corridors of power is as intriguing as anything that happens in the situation room itself.

But how disappointing that, as one of the more enlightened French presidents of recent years steps forward to take his place, the Dark Ages should fall on the City of Light. I'm not talking about the Eurocalypse – or even about Eurovision – but about the all-eclipsing scorn and fear surrounding the new arrival's partner, Trierweiler, known to many as The Rottweiler, and – apparently – our latter-day She-Wolf of France.

There she stands, gloatingly triumphant over La Republic and le wronged former spouse both, resplendent in an entirely unprovocative white coat and knee-length black dress, cleverly captured by an opportunistic lens during a gust of wind that has brazenly displayed the upper-leg seam on her natural tan tights, the hussy. There she stands next to Carla Bruni-Sarkozy, formerly the nation's foremost self-publicising, incendiary strumpet, now defeated and limply encased in an ill-fitting cheap suit that declares her all breastfeed and no fight. Gone are the Dior gowns of her heyday; Trierweiler probably wrestled them off her and poked her newborn in the eye for good measure.

Where has this vision come from? Is it simply that behind every man in power there lies a woman to manhandle and mythologise? Every so often, she's a media dream come true, such as Bruni, or a woman of the people, like Michelle Obama. Every so often, though, she's a Trierweiler. And then nobody knows what to do with her.

Trierweiler has so far avoided the limelight that comes with being in tow to a leader of men; she hung back during the campaign trail and has shunned the usual cutesy couple-shots that the Bruni-Sarkozys were so crazy for. You get the impression Hollande does not need to use his partner as a means of validation or vote-winning. And Trierweiler is a person in her own right, a journalist, a working woman – but how foolish of her to think she might be left in peace.

According to the stereotype, if you happen to be a French woman, you're either Manon des Sources or Belle de Jour, an ingénue or a femme fatale. We may think we have problems over here with gender perceptions, but just take a look at French advertising to see how the words objectification and floozy collocate just as well as, say, a naked woman and a brand of weedkiller or a cesspit rinse-aid.

But yesterday's photo op outside the Élysée Palace for Hollande and the female members of his Cabinet – all 17 of them – is proof that this is not really the abiding feeling within his country. It's the "Blair's babes" shot we managed 15 years ago. So how depressing, therefore, that the hyperbole being heaped upon Valérie Trierweiler is coming from our side of the channel instead.

Perhaps our inherent mistrust of French women stems from the heavily entrenched need in our own culture to be everything to everybody. In France, femininity is not a problem, and it can and does come with a side order of flintiness. In Britain, if you're anything less than soft and pliable, you're a harridan. You can be successful and serious or sexy, not both like Rachida Dati. Over here, you're either Holly Willoughby or you're Harriet Harman.

No wonder Samantha Brick dislikes French women so much; they're clearly much more secure than she is. There's a lesson to be learned here, and we won't find the answer by baiting The Rottweiler.

h.walker@independent.co.uk

Twitter: @harrywalker1