It’s not as if they haven’t been warned. If you can’t stand the heat of political scrutiny, as that hoariest of cliches (almost) cautions, kitchens are probably best avoided.

And yet there is something about the kitchen that ambitious politicians seem unable to resist, desperate as they are to present their exceptionally normal normality to normal people everywhere, in the hope that showing they can operate a kettle will be enough to persuade voters that they should be running the country.

This week it was the turn of James Brokenshire, the communities secretary, who, for reasons that were never made explicit but have everything to do with the imminent Tory leadership contest, granted a newspaper interview in the kitchen of his south London home. The accompanying photographs revealed a union flag cushion, a union flag mug, his smiling wife, Cathy, and four ovens.

“I hate it when, come Christmas, there’s not enough room in the oven,” Cathy explained (they also have two dishwashers). Fine. But four? No, they were just “two, normal, double ovens”, Brokenshire insisted, tweeting a picture of himself holding a cake in front of his four ovens (“#twoovens”), and appearing not at all weird.

In a curious coincidence, Dominic Raab, the former Brexit secretary, has also recently been interviewed in his kitchen, alongside his smiling wife, Erika, some lilies and a cookery book open next to some toast. Why did they need a cookbook to make toast, asked some. Isn’t that what all normal people do?

David Cameron invited the cameras into his home near Chipping Norton, Oxfordshire, in 2006. Photograph: Andrew Parsons/PA

What is it about kitchens and political interviews and photocalls? It’s partly a process of elimination, says Theo Bertram, a former adviser to Tony Blair and Gordon Brown. The office and the local pub are out, and “besides, if you don’t do it at home, what are you trying to hide? And maybe the interview will feel more natural and less stressful if you’re in your own home (it won’t).”

Living rooms, he says, “don’t work so well: it’s not easy to pretend you are ready to lead the country while slumped on a sofa in front of the telly … where it looks like you briefly disturbed them from watching the semi-finals of Ninja Warrior (which, secretly, they also think they could win).”

Thus, for his first “WebCameron” video in 2006, David Cameron was filmed doing the washing up while his children ate breakfast. Last year the Tory MP Grant Shapps released a picture of himself in his kitchen with 10 coffee mugs, apparently believing it illustrated dedication. Nigel Farage has tweeted a picture of himself standing to watch the Queen’s speech on a television balanced on top of a microwave.

But what if letting in the cameras reveals something worse than having four ovens – two kitchens, for example? Tom Baldwin, Ed Miliband’s former chief strategist, has described as a “cycle of despair” the episode in which the then Labour leader invited BBC cameras into his home during the 2015 general election campaign.

Ed and Justine Miliband filmed in the smaller of their two kitchens in 2015. Photograph: BBC/Enterprise News and Pictures

Miliband and his wife were filmed in a small kitchen that a Daily Mail columnist derided as laughably austere, before another journalist revealed that the couple had a second “lovely” kitchen. No, Miliband hastily stressed – that one was “just for the nanny”.

“The verdict from the media, both old and new, was that we had cynically sought to portray Miliband as normal and the whole operation had backfired into an authenticity disaster,” notes Baldwin. “It was hard to disagree.”

But do we really care, any longer, about politicians’ domestic set-ups? If the political system is in flames, Liz Truss’s croissant technique, which the chief secretary to the Treasury tweeted in detail this year, is not going to put out the fire.

Joey Jones, a former spokesman for Theresa May, agrees that the the kitchen set-piece showing a model family looks increasingly old-fashioned. The problem, he says, is “that senior politicians have their working life and their domestic life, and probably not much in between. They are just not very interesting people.”

He recalls an interview given by the prime minister during the last leadership campaign, in which she revealed – to the delight of her media handlers – that she had 100 cookbooks, and favoured Yotam Ottolenghi over Delia Smith.

“Looking back, it probably feels laughably trite, but in the context of someone who was very private and pretty inscrutable, that flash of creativity or unpredictability was rather seized on.”

In that context, it is worth recalling that Brokenshire was once described as having “the personality of a motorway car park”. Now he’s the four ovens guy. And who knows what next?