This week, in Trinny and Susannah Undress The Nation, the girls tackle the problem of the nation’s forgotten shoppers – men. Trinny & Susannah launch a campaign to delve deep into the male psyche, unearth the root of the problem, and create a new nation of well dressed men.

Hundreds of civil engineers in London are stunned when Trinny and Susannah swoop in on their dress-down day. They round the men and coax them into their pod to reveal how and why they dress like they do and Trinny & Susannah are shocked at the results.

“You’re wearing a woman’s vest over a man’s t-shirt!” says a shocked Trinny.

“You’ve got amazing coloured eyes but you look like you’ve just crawled from under a stone,” adds Susannah.

Expecting a few faux pas Trinny and Susannah soon realise that they have an enormous problem on their hands. The girls decide they need to see where this crisis stems from.

They hit the high street and go undercover to observe just how men shop and find out why they always get it so wrong.

With their hidden cameras, the girls spot a text book case and pounce on 28 year old window cleaner Paul Wright and girlfriend Emma.

“You need to be more streamlined. You need to get a little bit of elegance in you and a little less thug. I did think football hooligan when I saw you first,” advises Susannah.

The girls conclude that they need to come up with some kind of method that’s going to make the shopping experience easier for men but to do this they need to get inside their heads and see what makes them tick.

Trinny and Susannah take a trip to East London’s finest dog track in Walthamstow – one of the last bastions of British maleness where women are few and far between.

Susannah says: “They’re all shouting, they’re all shouting, they all understand each other, it’s a foreign language but they all understand each other.”

After grilling the men at the races and seeing how they work, the duo have a eureka moment: they see the way men crave information and the way they like it presented to them – simply.

The girls decide that men come in six basic varieties: Man boobs, beer belly, short legs, thick neck, broad shoulders and skinnies. They come up with dos and don’ts for each body shape and decide that a simple chart format could work;

The girls need to get the rules out there so approach a well know department store in London. Their plan is to turn the men’s department into a female free, men only, shopping oasis where each man will be armed with Trinny & Susannah’s new rules.

Firstly they decide to road test the rules on some Cumbrian slate miners, men they consider to be the least vain. They head down the slate mine to surprise the men but Trinny might have to commit a sartorial crime of her own;

“Oh God! I’m going to have to wear a fleece. Do I really need to wear this?” questions Trinny, donning walking boots, hard hat and head torch.

Trinny and Susannah decide to take the men on a shopping trip to Newcastle. 41-year-old Mark Weir lives in his work clothes and couldn’t care less how he looks. 38-year-old Martin Nicholson does care but hasn’t shopped for himself in seven years, while 29-year-old Graham Robson hasn’t bought a single item of clothing for over a decade and believes it’s a woman’s chore.

After being left to their own devices Trinny and Susannah give their verdicts on the men’s own choices:

“I’d say you’d gate-crashed, you’re the help, the waiter, you were caught short with your trousers in somebody else’s door and you quickly put something else on and I’d say you’re about, ‘I’ve done well, look at my jacket’,” says Trinny.

After a practice run the girls are worried that the rules aren’t working.

“A set of clothing rules may seem very simple to us extraordinarily brilliant women but to blokes they seem to have a problem getting their heads round it,” explains Susannah.

The girls call upon an ad agency to simplify the rules even further, and with this in mind, they base the rules upon the Highway Code – The Male Dress Code.

The Male Dress Code is perfected and Trinny and Susannah invite six examples that represent each body shape of the male dress code down to their department store.

They include, Martin East who has always been embarrassed by his skinny body and hasn’t shopped by himself for ten years, 35-year-old Ross Campbell who detests his beer belly and 35-year-old David Pomoroy who has lost nearly five stone.

Also joining them is 38-year-old Clive Starr with his man boobs, thick necked Paul Wilson and short-legged Carl Salbridge.

Trinny and Susannah show that with direction men can dress well and these men are the proof but will the code translate and create a nation of well dressed men?

Tuesday 13 November 2007 8:00pm – 9:00pm on ITV1.