Who wants an untidy slob as a husband? And who's got one?

Despite Gordon Brown's Opus Dei act of penitence, the only sin he confessed to was using the wrong word. When Nick Clegg was asked to cough up his personal weaknesses on the Eddie Mair show later the same day, he said, after peering into the depths of his soul, that he was bad at "keeping his papers in order". This followed revelations by Sarah Brown and then Samantha Cameron that their husbands could be messy.

This very un-British election has been dominated by three men boasting. David Cameron and Clegg particularly have a good line in charming self-deprecation, but television salesmanship meant that the humour had to be dumped by the wayside. What took its place was a false humility and dog-whistle sexism.

Personal untidiness has become a euphemism for generosity, high-mindedness and, possibly, virility. If you said you don't cook or won't look after the children you would look old-fashioned and churlish. Samantha Cameron praised her husband for being a "fantastic dad", a talented cook and a "supportive husband". But she didn't want him to sound like her gay best friend, so she had to allude to his messiness.

Clegg made a slightly different calculation. If he is suspected of being a Euro technocrat (he speaks several languages, can ski, has Brussels engraved on his heart) what better expression of contrariness and patriotism than an untidy desk?

I am puzzled that untidiness is considered appealing in a politician while in business it is a pathetic flaw. I have never read an interview with a CEO where he, or (in rare cases) she, winks and points at the donnish squalor of a desk.

The Goldman Sachs four who appeared before the Senate last week winced in dismay when they were asked to navigate fat, messy files to find incriminating emails.

The implication is that order is external as well as internal. If you are tackling the kind of public debt that an incoming government will have to, it is advisable to have your paperwork in order.

It is unimaginable that Margaret Thatcher would have been content in a Francis Bacon environment of creative mayhem. She tidied up after herself and everybody else. She understood the beauty of to-do lists.

But men want it all ways. They understand the tyranny of signalling both power and helplessness.

As the American feminist Letty Cottin Pogrebin once wrote: "Housework is the only activity at which men are allowed to be consistently inept because they are thought to be so competent at everything else."

Tidiness is the preserve of women. In men, it is comic or dysfunctional. The tidiness of George Clooney, in Up in the Air, is a sign of his alienation from humanity. If a woman is tidy, it is a source of pride. A female friend of mine was made desk monitor at work and took her duties seriously.

Of course, the tidiness-is-for-girls approach is passed from father to son. I have tried experimenting by telling my teenage son and daughter to pick up their own clothes and tidy their rooms.

A girl takes responsibility, although I am not aware of a tidiness gene, while a boy blithely continues to wear rotting pants.

Boys are conditioned to think that untidiness is a mating call, and eventually a wife/maid will answer.

Perhaps David Cameron has too much to lose to play the neatness card, but it really would be a sign of political and social change.

If businessmen are proud to be anal, why must politicians stumble around in a mess of their own making? It is an election tic and they should knock it on the head.

Sarah Sands is the deputy editor of the London Evening Standard