Leading Article: A nation split by the great British sandwich

As we report today, the condition of the British sandwich is causing great debate. So it should: sandwiches have much to tell us about our history and times. They are much digested; their meaning is less so. This morning, we attempt to rectify that - to stuff the bread of daily life with the cucumber of cool, philosophical reflection.

From its origin as the convenience food of a debauched aristocratic culture, the sandwich has been a measure of our national life, the original bread and butter issue. It was given its name when John Montagu, the fourth Earl of Sandwich, stayed at a gaming table for 24 hours, sustained only by cold beef between slices of toast. He had a bad press at the time, accused of indulging in "vicious pleasures, uncleanness and blasphemy". A typical member of the British ruling class, in other words. He was pretty hopeless at running the navy, too, which is what he did when he was not wenching, gambling, carousing and snacking. Still, all that is long forgotten, while his name lives on.

From the start, the sandwich reflected the mores and lifestyle of the nation - or at least the dominant nation, as it was a quintessentially English invention. The first recorded use of the word was in 1762 by Edward Gibbon, who wrote in his journal that he had dined at the Cocoa Tree, which "affords every evening a sight truly English. Twenty or 30 ... of the first men in the kingdom ... supping at little tables ... upon a bit of cold meat, or a Sandwich".

From such uncouth beginnings, sliced bread and stuff became popularised and refined. In the late Victorian or Edwardian period, cucumber or cress was placed delicately between slices of thin white bread without crusts - the mainstay of Merchant-Ivory Englishness and still critical to our cultural identity. Every summer at Wimbledon, 190,000 sandwiches are served (a detailed breakdown is not available, but most of them must have been cucumber).

And this century saw the advent of the Fordist sandwich. With mass-produced, mechanically sliced, square bread came uniformity. The standard 6in x 3.75in x 0.5in sandwich was in every lunchbox and pub in the land. Its counterpart was "unreal" ale, Watneys Red Label and the rest. Its main filling was margarine, processed cheese and processed ham (with as much water as industrial chemists like Margaret Thatcher could make it hold).

As we became more aware of Britain's relative decline, the sandwich stood as a symbol of our second-rateness. The British Rail sandwich, curling at the corners, became a national myth, although no one can quite remember eating one. It stood as an indictment of statist, bureaucratic corporations.

Then came the sea-change. Mrs Thatcher was promoted from retired chemist to Prime Minister. She swept aside James Callaghan, prices and incomes policies and the British Rail sandwich. The first thing her government did was lift exchange controls: the country was flooded with foreign sandwiches. The baguette became the junk food of choice of the hurrying yuppie. Real mayonnaise replaced salad cream. The Eighties had arrived and niche marketing took off. Ciabatta bread - bread with funny bits of walnut or olive - any exotic filling you like, preferably with French and Italian names.

Of course, the great British sandwich had always reflected the influence of key groups of immigrants. The Italian sandwich bar, the Jewish salt- beef sandwich. Even the kebab - but that is not really a sandwich, and there is no room in a serious leading article for a digression on the subject of pitta bread, burger buns or other false-sandwiches. What was important was that, in the Eighties and Nineties, the sandwich became a pounds 2bn-a-year product, subject to the same pressures of globalisation as the rest of the British economy. The breakthrough was the invention of the cheap see-through plastic triangular box, which allowed ready-made designer sandwiches to be sold in supermarkets. (To realise what a revolution this was, try to remember how ready-made sandwiches were sold before. Clingfilm features strongly in many memories, although before that it must have been cellophane and greaseproof paper - no wonder British Rail had problems.) Now, marketing is all: segmentation, high added value, foreign chic. Even the British Rail sandwich underwent the marketing revolution, in cartons signed by Clement Freud.

The result, as yesterday's Sandwich of the Year announcement confirmed, is that some British sandwiches are now among the best in the world - another benefit of 18 years of Conservative rule which John Major forgot to trumpet in his election campaign. The much-vaunted American sandwich, for example, is gross, unwieldy and much of it is likely to end up down your front, while the "club" version must be one of the easier ways to charge money for old rope known to restaurateurs. Only le sandwich, the genuine French article, can compete with Britain's best now.

But - and this is the most serious point - all across Britain there are still people eating the institutional mid-century sandwich, the Boots Shaper, the stale-bread ploughman's, the ham slab.

Ours is a nation divided, and the great challenge facing the new Labour Government is whether it has the courage to overcome this yawning chasm at the heart of our society. Can fresh mozzarella, pine nuts and pesto be made available to the many not the few? Can Peter Mandelson, once filmed preparing a rocket salad, lead us to the Blairite uplands of sun-dried tomatoes for all?