Women lie a lot. In particular they lie about politics and clothes. But while it is no big deal if your best friend tells you she supports Barack Obama for his superior politics when you know it is because he looks elegant, powerful and presidential, it's much more serious when she tells you that you look gorgeous in a dress that resembles like a tent.

So you think I'm too tough on my sisters? Pollsters say women gave Obama a big bounce following last week's joust with John McCain in Nashville. Think it was because of his policies? Get real. It was because they loved his looks and insouciance and were troubled by the breathless, diminutive marionette McCain.

personality

But then women have always been strong on the politics of personality. Sometimes this is reprehensible -- remember Unity Mitford's crush on Hitler? -- but mostly it's realistic. Women rightly recognise that personality is primary -- which is why they wanted Clinton, Blair and Ahern.

As we see from those Three Amigos, when women lie about preferring policies to personality, it doesn't do any damage because the people they pick for personality reasons are usually the right people. But when lying about what I look like in a dress, they do dreadful damage.

Because, going back to when I was six, no other woman has ever been able to judge when something looks good on me. Or if she did, she lied about it. Let me give you two recent examples from my own vast store of bad experiences.

Two weeks ago, I attended my 10-year school reunion. I chose safe with a playful twist: a demure Roland Mouret-esque black dress cheered up by a ruby-red patent croc belt and vertiginous bordello-burgundy patent heels. All night, men told me I looked swell, while women stared in reptilian silence.

bonfire

Last week the exact inverse happened. Feeling avant-garde -- ie insane -- I went to a party wearing the current folksy fashion trend: a long gypsy skirt, paisley-print blouse, cream gilet (a suede sleeveless jacket with fur piping, which should be burned on sight) which basically added up to a barrel standing in brown fringe boots.

All night I felt fat, frumpy and uncomfortable -- and looked it. Did anyone alert me by asking whether I was going to live with the gypsies? No. Instead women were all over me like poison ivy telling me how great I looked and how gorgeous my lumpy gilet was. My male friends were horrified. That night I threw a Bonfire of the Carries: I burnt all the Carrie Bradshaw-inspired sartorial calamities from my wardrobe. Very Stephen King.

conspiracy

And it's not just me. In a boutique last week I noticed a conspiracy of women hovering outside a fitting room door. Suddenly, I heard a trill of "you look stunning!" The object of their appreciation -- a pumpkin-shaped young woman -- tentatively emerged sinking in a sea of diaphanous, Mediterranean blue silk. More sea monster than little mermaid.

honesty

We all know the old adage that women dress for other women. More fool them. Because the only sound clothes advice a woman will ever get is from her boyfriend or husband. Why? Because they have a vested interest in you looking good whereas some of you are their only vested interest.

That's why I urge women to approach this month's Carrie-tribute collection by Sex and the City stylist Patricia Field for Marks & Spencer with caution. Because you have to ask why M&S -- bastion of sleek, chic, understated style -- would belatedly embrace fussy, decadent, fast-fashion Carrie when everyone is moving towards recession chic; which means investing in shift dresses instead of smock dresses and stilettos instead of wedges.

But while we're waiting for M&S to get it right, we should make sure to take a man who loves us on shopping trips. He'd be honest enough to tell us when we look like Carrie and when we look like a carrier bag.

- Gwen Halley