Focaccia, as it was known then, was served up as a snack or appetiser. A slice of history: how pizza became a fast-food favouriteThe most basic of pizzas is thought to have originated in prehistoric times, as bread cooked on flat, hot stones.It wasn’t until about 1,000 years ago that the herb-and-spice-covered circles of dough became popular in Naples. “The thing about changing our menu,” explains Page, “is that our regulars believe they know it so well they never bother looking at it.”And therein, perhaps, lies the problem. Pizza Express also hopes to lure new diners, and rekindle the romance with departing regulars with two new pizzas, one with chicken, the other with parma ham, being trialled for the first time this week in seven London restaurants There are even rumours of a daring new cheesecake. The new restaurant in London’s Haymarket has a significantly “cooler” interior and, shock, a modish new logo that is a million miles from that familiar blue neon circle designed in the Sixties. But the pizza doyen is, finally, making a belated attempt to fight back: 80 restaurants are to be refurbished over the next two years.

“Things are still going very well.”Chief executive David Page is the first to admit that “Pizza Express is slow in changing, it takes us about 10 years to do anything”. Peter Boizot, who at 70 is still president of the company but also now occupied with owning Peterborough United FC, is vehemently against offering other Italian food, however.”It’s always been a question of ‘KISS’ – Keep It Simple Stupid,” he says bullishly. Johnson appears to be cocking a snook at his former employers – and the boring electric ovens in some of their branches – by declaring on Strada menus: “All our pizzas are baked in our forno a legna – traditional wood-fired oven – to attain the authentic smoky flavour that we believe is essential to real pizza.”Both chains have benefited hugely from copying, and modernising, the Pizza Express formula, including offering a broader menu than a list of pizzas. Its standard Margherita pizza is also 10p cheaper than at Pizza Express’s, at £4.85.Meanwhile, Strada, another growing pizza chain, set up by former Pizza Express executive Luke Johnson (of The Ivy and Belgo fame), is also making inroads into its traditional territory. The look is sleek, modern and stylish, with candles on every table adding a romantic twinkle to the subtly dimmed lighting. There isn’t a single wood-burning stove in sight.Directly opposite is a branch of one of Pizza Express’s deadliest enemies, Ask, and the contrast could not be more marked.

True, there is an uninterrupted view of the kitchen – and three desultory chefs looking bored shoving pizzas into an ugly conventional oven. The black and white floor tiles are worn, the walls scuffed and the “art” on them consisting of a few tired, nondescript posters. The unforgiving white lighting in my nearest branch, in Chiswick, west London, would be better suited to a dentist’s surgery. And its Fulham Road branch in London was chosen by Prince Harry for one of his first dates a couple of years ago; perhaps a surprising choice when most Pizza Expresses strike their diners as anything but seductive.The d?r is deadly.

He lingered for a couple of hours over lunch most days at the chain’s Lincoln branch, always ordering an extra egg but no olives on his favourite Fiorentina pizza (£7.90) while working as a stage hand at the Theatre Royal on day-release from his North Sea Camp open prison. The sturdily built party chairman, Charles Clarke, was recently spotted there scoffing two pizzas in one sitting (presumably because they’re so small) while apparently decrying two of his most senior Cabinet colleagues.The disgraced Tory peer Lord Archer is – or rather was – another fan. The New Labour mob still likes to plot its next political move over a Napolitana and Chianti in Pizza Express’s Westminster branch in Victoria Street. (For the record, I could detect only four olives and the same number of parmesan shavings on my £6.95 Soho Pizza this week, supposedly a concoction of rocket, parmesan and olives.)There are still loyal customers, of course. The restaurant critic for The Spectator, annoyed by its “titchy” portions, wrote that £7.50 for a pizza sporting just one and a half anchovies was tantamount to pricing these hitherto humble fish “up there with crack cocaine if not plutonium”.