Is it acceptable, given the current climate, to pay upwards of £300 for a pair of ballet flats? I doubt the lovely people at my bank would think so, but let me explain…

Firstly, I live in them – I always have and suspect I always will. When my mother was my age, she did too. So unfashionable were ballerinas back then that the only place in London to buy them was Anello & Davide, purveyor of footwear for dance companies.

Now, thanks perhaps to Kate Moss, they are a staple in every off-duty, fashionable wardrobe and in my on-duty wardrobe, too. But there's a problem. Not only, according to my podiatrist, do they play havoc with toenails, but their flatness is often more uncomfortable than a heel.

Enter the Lanvin ballerina. When Alber Elbaz first arrived at this label in 2002, he accessorised his entire debut collection with shoes just like my mother's: aged and with a slender, paper-thin sole. Over the past decade, he has perfected this design and, truly, these are now the finest ballerinas in the world.

Firstly, this is the only acceptable face of the hidden heel. Tom Cruise, take note. It measures no more than a centimetre, just enough to tilt the ankle in a flattering way. The rest of the inner sole is cushioned, too: walking is a pleasure. Lanvin ballerinas have subtly elasticated edges that hold the foot prettily and they are crafted in fine leather that is deceptively sturdy. They last, then, wearing in gradually and improving with age.

It's small wonder that there is barely a fashion insider who doesn't carry a pair in her bag.

Susannah Frankel is Fashion Editor of 'The Independent'