The more everything becomes the same, the more the ubiquitous branding begins to grate, the more everything looks like it belongs in a mall – the more the few surviving caffs represent a refuge. They are a counterintuitive delight, a wallow in the tinnitus buzz of frothing milk, underpowered neon and the comfortable retreat of vinyl booths. The caff is a British institution, something equivalent to the US diner (drabbed down to slip seamlessly under grey British skies), a last bastion of unhealthy food, family firms and working-class culture. And it is disappearing eye-wateringly fast. Seven years ago I strolled around London writing what started as a guide and ended up almost an epitaph, discovering and rediscovering the last few surviving examples, scoffing bacon and eggs, gulping down the remnants of a culture once fuelled on strong tea but now forced to subsist on a paper cup of nearly boiling water with a tea bag floating disconsolately on its surface. By the time the book was published a number of the featured caffs had already disappeared and in the intervening years at least half of them have gone.

The caff is a peculiarly metropolitan and cosmopolitan cocktail of influences. There were the sober Edwardian dining rooms providing cheap meals for working men and there were the buffets and transport cafés of the inter-war era (the grey English repression of Brief Encounter). But more importantly there were the Italians who brought over their frothy coffee immediately after the war. The caffs of Soho gave the emergent tribes of teenagers somewhere to hang out before they could drink alcohol. Along with their espresso machines the Italians brought Lambretta styling and Formica counters to ration-starved London, a blend of US streamlining and continental urban chic. They adapted to local customs with a range of unhealthy foods based on Britain’s greatest contribution to world cuisine, the fried breakfast. And that was how it stayed. With their distinctive interior landscape of red and brown sauce bottles, salt, pepper and vinegar appearing like mechanically reproduced Morandi still lifes, their wood vinyl veneers, mosaic tiling, faded Luncheon Voucher and “Drink Milk” decals, they appear like something from another world.

The best examples, such as E Pellicci in Bethnal Green, not only survive but thrive. The Savoy of the caff world, Pellicci’s is a riot of Art Deco marquetry and exquisite details. It is now also, astonishingly (and admirably), protected, receiving Grade II listing from English Heritage in 2005. Meanwhile Soho’s Bar Italia has become a kind of anchor, an indispensible stop-off on the late-night London passeggiata; a brash 1950s blare of light, sound, worn Formica and superb espresso, it is more popular than ever. But if the futures of E Pellicci and Bar Italia look assured, the others are almost all in trouble. The past few years have seen the end of institutions including the New Piccadilly, a rock’n’roll staple once the heart of the Soho scene; the 1960s-chic Copper Grill near Liverpool Street; and the perennially shabby P. George on the Fulham Road, which appeared in Ken Loach’s 1967 film Poor Cow.

The caffs are the spaces of the everyday, of the ordinary, yet they distil extraordinary stories of immigration and ambition, faded hopes and fashions, of class and business; they embody the values of a different world in which corporations didn’t yet control consumption and places aimed at the working class could happily accommodate City boys and dustmen, gents and tramps. Yet if most of the caffs seem as busy as ever, how come they’re dying out?

I’ve been going to the same caff for most of a lifetime – the River Café opposite Putney Bridge Tube station – and I asked the proprietor, Rob Vernazza, what was going wrong. “I’ve been here for 20 years,” he tells me, “and I love it, it’s a community. But profits keep going down. We’ve been able to manage it till now because the whole family works here, mum, dad, my sister … they can work the hours. But when they retire it’ll get harder.” It’s the typical story of a family business – Rob’s parents arrived from Italy and worked all hours in the caff, he took over, but now he’s being squeezed. “We can’t buy in bulk like the chains,” he tells me over a cup of steaming tea, “and it’s hard work, I’m here 5.20am, 5.30am every day.” The key question though is can he see his own kids taking over? “It’s a family business and it’s wonderful being your own boss. If the whole family’s working you can be flexible. If they decided to continue it’d be great.” His answer surprises me: most other caff owners can’t see their kids continuing the business; they’ve moved on to better-paid, perhaps easier things.

But the River Café (Rob tells at least two callers a day that he doesn’t take reservations and that they might want the other River Café) is exactly the sort of institution that binds the city together. The default starting point before a Fulham match, it is also a haven for bus drivers, Tube workers, builders and music execs – the walls are peppered with photos from album cover and fashion shoots. The service is impeccable, the bonhomie a perpetual warm embrace. The decoration, from the stick-on Italianate scenes (now patinated with old nicotine and chip fat so they begin to look like old masters) to the shiny old tea urn and the exquisite Edwardian tiles, is imbued with a kind of essence of London. These familiar archetypes are disappearing in almost every big city – whether it’s New York’s Jewish delis, or Paris’s corner cafés – squeezed out by the chains and rising rents.

But when they go a piece of the city dies; there is no recreating their layers of use and their easy, cosy familiarity. Terence Conran has tried to revive the idea of the basic British eatery at Shoreditch’s Albion, and the S&M (sausage and mash, no, really) chain had a go, but both the inevitable self-consciousness and the wincingly high prices exclude the clientele they originally served. Buy a bacon sandwich while you still can for a last taste of real London.

Edwin Heathcote is the FT’s architecture correspondent.

The River Café, 1A Station Approach, London SW6 3UH; 020 7736 6296

E Pellicci, 332 Bethnal Green Road, London E2 0AG; 020 7739 4873

Copyright The Financial Times Limited 2017. All rights reserved. You may share using our article tools. Please don't cut articles from and redistribute by email or post to the web.