It certainly ain't looks. But they are all rather well off. Claire Seeber on the new wave of sugar daddies
"MONEY can't buy you love" went the song - but there was no mention of pretty young girlfriends. Rupert Murdoch has a new one of these. We all know Murdoch is an extremely powerful media tycoon who, it should be remembered, is also pushing 70. Until recently, he had a wife who was, apparently, charming and smart. Yet recently, he's been spotted around town with a much younger model.

Wendy Deng is an employee - and only 38 years his junior. A friend of mine used to work for him. "He was all right. More importantly he could fly you to Australia by tea-time if you fancied it. I'd say that's pretty alluring. Serious money is a buzz."

Now, Murdoch isn't, shall we say, the most attractive of men, but he is one of the most wealthy. Forget the Spice Girls mantra, it seems that young women are succumbing to Ugly Power. So are we trading our man's looks for his success?

My mother would curse under her breath as my sisters and I proudly brought home yet another handsome waster. Where were the rocket scientists, MDs and industrialists? I never cared; I've always had a weakness for a good looking, fresh face. I really couldn't be bothered with the "knowing" (read old and cynical) looks the Wendy Dengs of this world have to put up with.

As if often the case, men who take "power" girlfriends rarely manage to combine money, brains and looks. Perhaps ugly men have a hidden agenda; what they lack in looks they need to make up in other areas. So, while handsome men have more luck on charm alone, the ugly ones strive to become empire builders. Big on power, short on charm.

I once had the misfortune of meeting film director Michael Winner. I was a struggling young actress and he needed an assistant for his production company. I answered an anonymous advertisement in The Stage which demanded applicants supply a photo - a bizarre request.

When I arrived at his mansion for the interview, Winner instructed me to stand in the window while he looked me up and down. "After all," he smirked, red-faced and really rather short, "if you work for me, I would have to look at you all day." Well, I failed the Winner test and, of course, he didn't offer me the job. One can only hope he doesn't subject his amours to this kind of test.

These days I read of his culinary exploits in the papers. He is usually accompanied by his dancer girlfriend Vanessa, who is not only far prettier than Winner but, of course, also much younger. So what is she thinking? Well, benefits of ugly power can include a stronger sense of security: after all if you're beautiful and he's old, he's less likely to leave you (unless it's for Lolita herself). A powerful older guy can offer a younger woman a sense of protection, and there are those women who are attracted to a father figure.

As relationship counsellor Mo Shapiro points out, there just has to be an element of "the coup" about dating a successful older man. "But we shouldn't be too cynical," she says. "It's easy to judge others, but unless you're part of it, why should you understand someone else's relationship? Real love can grow despite a huge age gap."

Shapiro also suggests that a bit of mutual flattery can go a long way; while an added enticement for a very young woman could be that she's taken seriously by someone so powerful. So whilst most cringe at the thought of liver-spotted hand on firm young thigh, the girlfriend may be somersaulting with passion. Either that, or diamonds and Beluga.

Therapist Julia Meanwell is more brutal. "Obviously status is all in these relationships. After all, if Andrew Neil was a milkman, would he date the young women he does now?"

One of my sisters has a penchant for starving Northern artists with fantastic cheek-bones. She also has a theory that ugly men must be brilliant in bed; the logic being they have more to prove and so work harder. But I'd hazard a guess that a business magnate who calls the shots in the office is more likely to have his pretty young thing slaving away over him than vice versa.

Over coffee in Covent Garden, I recently spotted wrinkle-zone Peter Stringfellow. He had a young girl in tow, all dewy-eyed, clear skinned, and cellulite- free (I know this because her skirt was so damn short). Now Peter may not be classy, but he's got a bob or two. When you're 16 and struggling up from the street, Bolly in the VIP lounge and lifts in the limo is all very thrilling. And it'll give you the chance to climb.

Of course, beauty is only skin-deep. Even so, in a man's world, you'd be better off tearing your eyes away from the Lear jet, girls - and watching out for the sugardaddy leer.