This week I've been thinking a lot about supermodels. It's okay for me to do that, you see, because I'm a columnist. If you do that it's because you're shallow and probably a little bit lecherous, and you should go and have a cold shower at once and then go and buy the wife some flowers.

First off, there's all this Kate Moss business. Kate has been all over the papers because she's been "caught" by some enterprising individual with a camera phone snorting enough cocaine to not only put an ele-phant on its back but probably have it whistling Jerusalem as well.

The indignation of the tabloids has been illustrated by some rather grainy photos of Kate doing the deed which at first I thought were meant to be images of the face of Christ discovered on a teatowel by a pen-sioner in Wolverhampton, until the face of Christ on a filthy old oven-tray actually turned up in the pa-pers a couple of days later.

The surprising thing about all this, of course, is that anyone's actually surprised, let alone shocked, by it. Given that Kate Moss is stepping out with that Pete Doherty chappie, the Babyshambles singer who, leg-end has it, is on slightly more than nodding acquaintance with not only the old Colombian Marching Powder but also, apparently, blackcurrant-flavoured Lemsip.

Surely the point of supermodels is that they're meant to be badly behaved? We might not have to like it, and we certainly don't have to approve, but ever since Boadiccea slapped a bit of woad on, ran a Roman centurion through with her sword, and paused to allow some Ancient Briton to scratch her likeness with a bit of burnt stick on to a piece of dried animal skin, we've always liked our femmes to have a touch of fa-tale about them.

And any parents concerned that Kate is setting a bad example to their children should perhaps think a bit more carefully about who they encourage their progeny to view as role models. Kate Moss is paid a lot of money to pout in lipstick, underwear and frocks, not to provide young girls with something to write down on their careers forms in school.

Which kind of brings me on to the next lot of supermodels to cross my radar this week, those in the latest Marks & Spencer ad.

Now, no matter how many pairs of boot-cut jeans, camisole tops and frilly thongs M&S sells, it will still be for a lot of people the nice, dependable shop where Middle England buys its slacks, socks and new pota-toes (sorry, hand-picked, sunbleached Jersey Royal new potatoes with all the dirt scrubbed off them by the second cousin twice removed to the queen of a small European principality, as another M&S ad might have it).

So why, exactly, have Marks and Sparks employed for their latest campaign the godmother of supermod-els, Twiggy, along with a phalanx of the latest marques including Erin O'Connor, who at around nine-foot tall and something like a size six is hardly the epitome of modern British woman?

Any woman who has ever inquired of their other half whether their bum looks big in anything, or who has wiggled their arms looking for the slightest suggestion of bingo wings, would surely think that any clothes that look good on half a dozen of the world's top supermodels are probably going to make them look like ten pounds of horse manure in a five pound bag.

Forgive me if I'm sadly mistaken here, but wasn't it Marks and Spencer who once used a woman with a rather more representative size 14 or 16 figure shouting about how she was normal?

Presumably, M&S have decided that normal isn't good enough any more. Just look at their new potatoes.