Pity the poor soldier.

The one finally plucking up the courage to tell the then Prime Minister she was putting on her ear guards upside down before she went for that unforgettable ride, Britannia style, in a tank.

Pity the poor man as she explained, as to the terminally hard of thinking, that putting them on over her head would ruin her carefully coiffed hairdo.

(I was now about to write "the woman being laid to rest tomorrow", but on reflection I imagine the true blue Baroness will reserve the right to the odd birl in her grave whenever some upstart does something of which she would have strenuously disapproved.)

Instead, let us reflect that the woman who never really needed an armoured vehicle to ride into combat zones was also one who paid meticulous attention to her physical appearance. Almost as if she had concluded that, to be taken seriously, she required to exit each morning in pristine condition. Or perhaps being a woman not born to rule, because she required an outer appearance that would ensure inner confidence.

Thus, in the manner of the Queen on tour, Margaret Thatcher's female aide de camp would go through her wardrobe prior to visits to Brussels, New York or Moscow – selecting outfits for maximum impact or ordering a new set of battle dresses.

It would be comforting to think this was just a generation thing. That, like the equally hair-conscious Barbara Castle before her, there was a compulsion to turn out in Sunday best from Monday to Friday because dressing well was good manners, and, as granny always warned, manners maketh the woman.

But the dispiriting fact of the matter is that contemporary female politicians are also in thrall to the tyranny of the clothes police. A new survey just completed in the US found that where a male and a female candidate went head to head in an election, any reportage of the woman's appearance – even a flattering one – had a negative effect on her poll ratings.

And, to add irony to the mix, any male politician who ventures a compliment to a woman in public office can be roundly denounced by the sisterhood. The luckless Barack Obama took pelters this month for no more deadly sin than remarking that Kamala Harris, California's attorney general, was the best looking holder of that post in the country. Pleading veritas would not have got him off the hook either. The crime was mentioning her looks rather than her skills.

Yet the media continues to deploy double standards over coverage of political heavyweights. Only Michael Foot's much mocked donkey jacket (it was, his late wife noted in irritation, a perfectly smart navy three-quarter length overcoat) lent itself to widespread hostile coverage to rival any female wardrobe deconstruction.

For most male politicians the daily camouflage of a dark suit provokes no particular interest unless they occasion a mild stir by selecting a piece of neckwear which departs from the dreary self-coloured variety. For women the stark choice is to go for anonymity in a copycat trouser suit, or dress according to personal choice and risk any pertinent policy remarks being drowned out by the fashion commentariat.

Think of Jacqui Smith, promoted to one of the great offices of state as Home Secretary, but whose parliamentary contributions seem destined to be remembered chiefly because, on day one, she modestly demonstrated that women – good God – apparently have breasts.

But nothing more vividly illustrates the absurd pre-occupation with appearance over presumed capability than Hillary Clinton, whose various incarnations as First Lady, Democratic presidential candidate and Secretary of State caused many small forests to be felled in order to chronicle her looks and, er, assorted choices of hair style.

Here is legendary columnist Maureen Dowd, supposedly writing last week on Mrs Clinton's will she/won't ambitions for the White House in 2016: "Hillary jokes that people regard her hair as totemic, and just so, her new haircut sends a signal of shimmering intention: she has ditched the skinned-back bun that gave her the air of a KGB villainess in a Bond movie and has a sleek new layered cut that looks modern and glamorous."

When the sisters and supporters start weighing in with which haircut woos which voters, you know the game is up.

Not that Mrs Clinton is under any illusions on this front. As Secretary of State she clocked up tens of thousands of miles, often arriving for important bouts of summit work shortly after landing from long-haul flights.

How infuriating then to find the waiting press corps musing over many paragraphs not about the prospects for a Middle East peace settlement or relations with the Burmese regime, but whether a woman turned 60 should be allowed out with shoulder-length hair.

We might take a crumb of comfort from the thought that all this is a cross-party obsession. Nobody got more of a public makeover in recent political history than the Republican's wolf-in-designer-clothing Sarah Palin.

Her party remodelled her from the stilettos up before letting her loose on the American public forgetting until rather too late to check if she could manage joined-up thinking as well as power dressing.

Will we see another female PM on this side of the pond? Who knows? Who could have predicted the rise and rise of the grocer's daughter from Grantham?

I can, however, make the depressing prediction that if Number 10 ever again has a wardrobe full of skirts, their colour, cut and hemline will produce more column inches than the political acumen of their owner.