Philip Hensher: Mrs T proves that nothing evokes a political era like the clothes leaders wear

People used to go on about the Handbag. But for me it was all about the pussy-bow collar. What Mrs Thatcher used to wear defined the flavour of the 1980s in ways that the youth cults never did. The Jaeger suits at the beginning of the decade, in jaunty colours and a silk bow – the dreaded pussy bow – at the neck. The Chanel-ish suits in the middle. The Sod Off Everyone Gloriana-type ballgowns which, if memory serves, she wore constantly in the autumn of her rule. Wasn't there one at the Mansion House where the collar rose up behind her head like Ming the Merciless in the mood for executing someone?

Some of Mrs Thatcher's iconic outfits of the time are shortly up for sale at Christie's, courtesy of a private collector – God knows how the collector got his or her hands on Mrs Thatcher's best frocks in the first place, but we don't inquire. There is an amazing bright yellow one with an interesting side-button effect, very Chinese empress. There is one in ultramarine with tutti-frutti cuffs. There is a black one with a broad polka-dot lapel, which Mrs T gave a conference speech in – there's a photograph of her with an artfully matching pussy bow.

Marvellous. All of them British, not a single one of them anything other than massively redolent of a time, and a place, and a social milieu, and an overpowering personality. Interestingly, they used to be described, as Mrs Thatcher described herself, as a size 14. The size 14 of the 1980s, apparently, is the size 10 of today.

Politicians often struggle quite hard to be identified with a particular item of clothing, or a look, or a prop. Sometimes it happens without them trying (Michael Foot's donkey jacket). There is Harold Wilson's pipe. There was poor John Major's underpants. There is David Cameron's apparent attachment to the Boden dad catalogue.

Impossible to think of Norman St John Stevas without thinking of monogrammed red velvet house slippers. Sometimes – I know this is a recherché example – the 1990s Tory MP Dame Jill Knight will come into mind for no reason other than the massive herbaceous-border frocks she used to wear in the chamber.

But nothing comes near the Thatcher look as an embodiment of a political figure, and, actually, of a political creed. It would be absolutely impossible for anyone to put one of these incredible outfits on and then say out loud, "Do you know, I really think the public service needs to be applauded for the way it values consensus in debate." You just could not go on giving free state milk to children with one of those jackets on.

Mrs Thatcher was not, in fact, averse to discussing the detail of her wardrobe. At one hallucinatory moment in the 1980s, she took part in an Angela Huth documentary for the series Forty Minutes and answered questions about her clothes, including her underwear – she bought it from Marks & Spencer, she said, adding, "Doesn't everybody?"

The whole period between 1975 and 1990 was rather like that. To look at these beautifully made, highly performative garments is to see the other side of Vivienne Westwood, of Adam Ant's stage costume, of a shouty T-shirt that said FRANKIE SAYS RELAX. As Marie Antoinette could tell you from the other side of the guillotine, political beliefs fade and lose their meaning. But style, carried on with enough conviction, can last for ever.

Brad the gent

What a gentleman Bradley Wiggins is, really. Not everyone noticed his exemplary behaviour on winning the Olympic time trial. He was informed that he had the best time, but made no response, even though by then, the subsequent riders could not match his time, indeed had already exceeded it. He only raised his hands in celebration when the last rider had crossed the line.

This beautiful behaviour was interpreted by the BBC commentator, however, as Mr Wiggins not knowing that he had won, or not being able to believe it, or something. Nothing of the sort. As with the moment in the Tour de France when he slowed down, refusing to take advantage when his rivals suffered punctures from scattered tin-tacks, Mr Wiggins was just behaving with great respect and decency.

No one these days wants to be considered a gentleman. It hasn't seemed like much of an advantage for decades. But to behave consistently well, like Mr Wiggins, and to do the right thing without being ordered to is the best lesson the Olympics can give us. We're not going to ride as fast as him, but we can all endeavour to raise our manners to the status of ethical principles.

Must 'Vertigo' look down on the rest?

Interestingly, the once-a-decade poll of Sight and Sound into the greatest films ever made has moved Hitchcock's Vertigo into the first place, replacing Orson Welles' Citizen Kane. It's curious, however, that this exhaustive poll of the world's critics couldn't find anything later than 2001: A Space Odyssey in their top 10. Have no films scaled the heights since 1968? What about Pulp Fiction? Or anything funny, like Tootsie?

Well, we all have our personal lists. It's difficult to know, however, whether we are living in a golden age of cinematic archive or not. From one point of view, it is easier than ever to source classic films. You used to have to wait until your local repertory cinema decided to show Last Year at Marienbad. Now you just get it off Amazon.

On the other hand, those repertory cinemas have now almost all gone, and the curatorial function they performed of introducing people to the classics of the past has disappeared. You are not going to watch Juliet of the Spirits if you've never heard of it.