Politicians on holiday: Time for a dressing down...

They know they'll have to pose for the cameras. So why, asks Harriet Walker, do politicians find holiday snaps so hard?

Forget the war in Afghanistan – we shall fight them on the beaches, as Churchill said, and he may well have been referring to the Camerons' recent holiday snaps.

Of course, no one is safe from the fashion police these days. Forget PMQs and battles at the dispatch box – a simple stroll along the beach became a hike through a sartorial minefield for David Cameron this week as his choice of casual classics was pitted against Gordon Brown's more formal countrified look.

Dave and Sam chose light and breathable holiday-wear to take the Cornish sun and sea breeze (or is that the winds of change?) on their break in Harlyn Bay, near Padstow – she in a vest and floral print maxi-skirt, he in a loose-fitting Aertex polo shirt and a pair of shorts which, on closer inspection, reveal themselves to be swimming trunks.

Sartorial multitasking is the name of the day when it comes to beach chic. Not only are both of these outfits practical for coping with a great deal of hot air – Dave's plunge-ready lower half also flags him up as a man of action, a fashion lifeguard patrolling the ever-turbulent political seas.

Meanwhile, over in Suffolk and far from the twin Sloane beacons of Rock and Polzeath, Gordon and Sarah enjoyed a more formal approach to holidaying. Maybe Sarah had a style conference with Carla Bruni during her recent visit – she's certainly channelling a bit of Jackie O in the English countryside, with her smart shift and girly cardie combo.

Gordon, on the other hand, was all open collar and cuffs, with a provocatively mis-matched blazer and jeans. He may well be the only man who can make buttoned down look buttoned-up.

Machiavelli knew the importance of dressing to impress. Before leaving his rustic villa and entering the murky corridors of Florentine power, he would "re-clothe appropriately" and don "garments regal and courtly". But then, Machiavelli didn't have to contend with celeb-loving voters and sneaky wardrobe spies from the newspapers – and even he probably shrugged off his doublet and rolled down his hose for a walk in the hills.

David's attention to detail is questionable, matching the stitching on his shorts to that of his T-shirt, whereas Gordon's blazer and jeans combo could have been improved with more colour co-ordination. He must know by now that nothing in politics is black and white, let alone black and ecru. This is a turn-up for the books – if not for his jeans – as we all know the Prime Minister is the more fastidious of the pair.

So Dave and Gordon have got a bit to learn, but their wives appear already to have learnt it. Samantha Cameron, whose sister works at Vogue, has become a champion of casual causes, always elegantly groomed, whether in high-street or high-end pieces, while Sarah Brown has a more down-to-earth outlook, as her French counterpart Carla agrees: "Sarah's style is classic – and she hasn't done 12 years of modelling like me, so she doesn't go looking for clothes like I do."

But, as every fashion victim asks themselves at least once a week, is it clothes that I'm looking for, or just acceptance? All of these political outfits look like they're trying too hard, and that's a fashion no-no. Gordon seems ill at ease without the restraints of a tie and cuff links, as if he straps on his policies with them. And Dave looks rather like an over-grown schoolboy in his Eton-issue PE kit shirt and shorts. Maybe the cat ate his manifesto.