It's rare that I view a photo of a group of strapping young men and am filled with an overwhelming desire to strafe them with an Uzi. Or to drop them all in the middle of the Borneo rainforest with some dinner jackets and a bottle of Bolly and shout: "See how far that gets you, mate." Seething hostility verging on psychosis was my presiding emotion on seeing the 1987 picture of the Bullingdon Club published in a new biography of David Cameron written by Independent on Sunday journalists James Hanning and Francis Elliott. (The Bullingdon Club, for those of you who remain in blissful ignorance, is an elite "invitation-only" drinking and dining society, based at Oxford University.) Have you ever seen such a bunch of arrogant, inbred, sphincter-faced tosspots?

The Bully boys may, I suppose, claim something satirical in their toffee-nosed swagger - poised as they are as if about to thrash a brace of footmen for insubordination - but nobody I know is laughing. Nor do they give a monkey's about whether Cameron smoked cannabis or not while he was a student. I suspect most people wouldn't give a damn if he'd mainlined heroin and lived in a brothel. But the shaming evidence that he once flaunted himself as the living embodiment of floppy-haired, Bride- shead-style privilege has the potential to decimate his credibility. And I suspect it is women who will be the most repelled.

I didn't meet a single female last week who hasn't expressed skin-creeping revulsion in reaction to this picture. "It's the sort of thing that makes you want to go and shag a load of Geordie brickies just to wipe the image from your memory," said one friend. "Bring back Prescott, all is forgiven," said another. "I bet you every woman can look at the picture," said a third, "and see a boy who reminds them of the bloke they most regret sleeping with. The one who couldn't remember your name in the morning. Wankers." (Apologies, but the Bullingdon photo induced unprecedented use of obscenities in even the mildest-mannered females.)

I'm the first to admit I make a crappy class warrior. When my grandchildren ask me: "What part did you play in the great class war, nan?", I will say: "Don't call me nan, darling, that's so non-U," before confessing that I sat in front of John Craven's Newsround circa 1984 saying: "Why don't the miners leave the poor policemen alone, Mummy." It's not my fault. I grew up near Sevenoaks, a town where socialists posed a distant, mythic threat like vampires in rural Transylvania. One girl I went to school with had parents who voted Labour, and once when we drove past their house my mother said, like Miss Marple unearthing an important clue: "See, their door is red." Also, like many girls who glutted on the Brontës, Jane Austen and the Mitford sisters, I tended towards a wildly over-romanticised view of aristos - an idea that was allowed to flourish unadulterated for years, until I met some real toffs.

As someone who's been castigated for having a posh voice, I'm the first to agree that inverted snobbery is as insidious and hurtful as the straightforward snooty kind. Until you look at that Bullingdon photo. There's a difference between discriminating against someone because of their accent and origins and being prejudiced because a person chooses of his own free volition to don "royal blue tailcoats with ivory lapels" and behave like a congenital moron.

We are told Bullingdon Club behaviour consisted of drinking yourself stupid before trashing a restaurant and offering the proprietor a fistful of "large denomination notes". I would have liked to see anyone try that stunt at my parents' pub. My Dad would have blasted them to Blenheim with his gun. Other anecdotes include writer Harry Mount's account of "being rolled down a hill by a Hungarian count", and Boris Johnson's talk of "dark deeds involving plastic cones and letterboxes". I once belonged to a club devoted to wilful misdeeds, such as posting litter through the village letterbox and strewing debris across people's bedrooms. But The Terrible Two Witches' Cats only had two members - Polly and me - and we were only seven.

Arrested development is a pitifully inadequate term to cover the antics of the Bullingdon boys. And I suspect any ire roused in female breasts by the photo stem from a fairly widespread experience ofencountering this brand of emotionally stunted ex-public-schoolboy. Chaps whose interest in womankind was largely confined to whether you were called Topaz and had been to Benenden. The worst offenders were often Old Etonians. This sounds chippy, but you'd be chippy if you walked past some OE fogey in an Oxford college's grounds of a February night and heard him mutter: "Horrible women, they are melting the snow." If you were told that current Etonian slang for ugly girls was: "She mings for Greater Manchester". If you met one Bullingdon member about 60 times and he even visited your digs on numerous occasions, but he often forgot your name because you existed beyond his social parameters. If Oxford taught me anything, it was the mantra that "poor boys are more fun".

I wonder what it taught David Cameron. That you can break the rules and restaurant windows and get away with it? That a wad of notes sorts out awkward questions? This almost certainly does him a grave disservice, but one lesson is clear to all of us: you should never pose for a photo you may one day regret.