The Prime Minister is giving a speech. He’s talking about things that directly affect you, that influence you vote, that might make your life better. Or worse.

The thing is, you’re transfixed by his trousers. They’re what you’d call ‘a fail’. ‘He should be flaunting those curves’, you think, ‘not hiding them away.’ You’ve studied them for five minutes already and nothing, now, is going to wrest your attention back from his strides to his soundbites.

That's ridiculous, isn't it? But that’s the way it is for female MPs: their work and words are hostage to their wardrobes. They are subject to the same scrutiny as popstars and models, despite their work having nothing to do with their appearance.

When Labour MP Stella Creasy spoke out in parliament against Page 3, she was accused of hypocrisy by the Sun’s political editor for wearing a ‘bold’ PVC skirt, as if her clothes were somehow related to the lack of them in the newspaper.

And Home Secretary Theresa May more often than not hits the headlines for the cut of her coat rather her jib – those leopard print shoes of hers have proved almost the perfect foil to us hearing anything of any worth from her. That’s the way the media has it, at least.

This pernicious undercurrent eddies up into news and current affairs, and begs us to appraise and approve our political representatives in the same way we do our reality TV stars: not for what they are saying, but for whether they wear enough high street, or have an eye for print. It’s one-eyed to do this to the likes of Michelle Obama and Samantha Cameron, of course, a lawyer and a businesswoman respectively. But they aren’t even elected representatives.

Dress sense is edging onto the polling card when it comes to women in politics, even as we engage more frequently and openly about the everyday ramifications of feminism. It’s Susan Faludi’s Backlash mark ii: a covert means of undermining women as they become more politically prominent. The higher we climb, the more susceptible we are the old rod that has always been used to beat us: our appearance.

It shouldn’t matter, but it does. We’ve all felt the vicarious thrill of scanning an outfit and working out whether we like it or not. It’s only natural – the problem comes when that’s all we do, when we fail to realise when it’s appropriate and when it isn’t. If you’re in any doubt, comedian Sarah Millican is very good on the subject.

‘I thought I had been invited to this illustrious event because I am good at my job,’ she wrote recently, in response to Twitter trolling. ‘I’m not a model, and I have never learnt how to pose on the red carpet.’

As the public role of women has evolved and adapted, so too have those who represent us in the public sphere. The first woman in parliament, Nancy Astor, was an aristocrat and socialite – practically our media meat and drink these days. But during her time in the house, she helped lower the legal drinking age. Her modish apparel wasn’t a barrier to her work, and it didn’t form part of the commentary at the time.

30 years later, Barbara Castle was elected during the Labour landslide of 1945. Obituaries note her attention to dress and her immaculately coiffed red hair, but they linger more over the fact she campaigned for equal pay for women, and overhauled road safety legislation.

And Margaret Thatcher was famous for her suits and her handbags, but they in no way overwhelmed the seismic changes she brought about as Prime Minister. Rather, her character on Spitting Image was presented in a man’s suit, such was her forthright reputation for getting things done rather than being a woman who wore clothes.

Since these female grandees of our political system made their marks we seem to have regressed, not only in numbers and representation, but also in our response to those in Westminster. Appearance politics are on the rise for both genders, but it affects the male message less. If we choose to pass comment on David Cameron wearing office shoes on the beach in Cornwall, we still hear what he has to say when he’s on duty.

As clothing codes for women in the workplace – for everyone, in fact – have relaxed, the scrutiny brought to bear on those very choices has increased. It’s the very opposite of the changes we’ve seen in fashion recently. In that sphere, clothes have become increasingly practical and pragmatic, de-formalised and to some extent defeminized, according to the empowered and modern women wearing them.

Where does it end? Will it, in fact? The spectre of TV debates raises the spectre of more of this, not less. The men have it less tough, you might argue, because all they wear is a suit. Well, Angela Merkel has tried that approach, and someone took the trouble to point out how many times she had worn the suit in question. So female MPs are damned if they do and damned if they don’t.