Whatever his other lapses, Prince Harry is a chip off the old block in one respect. The "fucking frog" insult he is reported to have levelled at a French chef at his local pub can claim direct descent from his great-grandfather at sixth remove, George III, who instructed the boys at Eton to learn to "hate the French". In both cases, the words seem to come naturally: in 2002 as at the end of the 18th century, there is nothing the British love so much as to take pot-shots at the people across the Channel.

Even the tabloids have finally given up portraying the Germans as goose-stepping closet Hitlers; Italians are seen through the prism of Chiantishire, rather than as bottom-pinching ice-cream merchants; Spaniards are no longer "dagos"; and jokes about the Irish ran out of steam before the turn of the century.

But the French are different: l'exception francaise proclaimed by the heirs of Joan of Arc and Charles de Gaulle is a source of constant baffled resentment to the British - or perhaps, in light of the auld alliance, just to the English.

In need of a modern historical put-down? Refer to the defeat of 1940 and what followed. Culture? Dismiss France as a desert that hasn't produced a decent film/book/ play for as long as anybody can remember. The media? Note the paucity of French national papers, and add, with a chuckle, that they could do with a Sun or two. As for gastronomy, everybody knows that one eats better in London than in Paris these days, and that French cuisine is badly cooked, bland and lacking in creativity.

Contrast the fascistic repression of Paris with the let-it-all-hang-out liveliness of London; and as for that guff about noblesse oblige, politesse and raffinement, we all know that the French are rude, inconsiderate and selfish, taking particular pleasure in unleashing their least attractive characteristics on long-suffering Brits.

In the time-dishonoured tradition of racial stereotyping, this, and much more, depends on a few generalised instances. Vichy was two generations ago, and the French media show an interest in the world that is increasingly rare here. Being a city that works hardly makes Paris a temple of fascism, nor does a failure to write in English mean that French literature is dead. A few highly starred restaurants in London cannot outweigh the legion of French establishments that nurture culinary standards in a way undreamed of in Britain.

But you don't even have to cross the Channel to play the game. This month, Julian Barnes has become a surrogate punching bag with the publication of a collection of essays on France. French esteem for Barnes was taken by several reviewers to be a sure sign that he is deeply suspect - along with Ken Loach, who may, according to one critic, owe his popularity in France to the way his films make Britain look like a dump. One review of the Barnes book even managed to list France's refusal to import our mad-cow beef as an example of its national self-disgrace.

Late last year, the bouncy, imaginative comic fantasy Amelie was treated as if it were an artistic litmus test by critics who, although they didn't get the jokes, found it a convenient baton with which to beat the supposed corpse of the cinema that produced Jean Renoir and the nouvelle vague.

The way in which the French take themselves seriously inevitably opens them to ridicule. A nation whose leaders talk of la gloire and the sacred nature of l'Etat are sitting ducks for hard-headed Anglo-Saxons. Tony Blair may reminisce about his time serving in a Paris cafe, but Margaret Thatcher showed herself to be of sterner stuff when she boycotted the 200th anniversary of the revolution.

But what the French are, or are not, is beside the point. More interesting is why the British embrace things French on the one hand, while simultaneously displaying a Prince Harry-style contempt on the other. There are 12 million journeys from this country to France each year; the Eurostar is crammed; village streets in the Dordogne are lined with cars with GB stickers; newspapers run endless guides to a weekend in Paris; books about British writers setting up home in rural France spin off the presses; we buy baguettes, drink Perrier and sip coffee in cafes; we even have to admit that les Bleus set the world football standard.

And yet, just below the surface, we remain convinced of our superiority. The French, we feel, must be secretly jealous of us, of our dashing Prime Minister and our outward-looking, on-the-move society. But what if it were the other way round?

What if, as NHS patients are sent across the Channel for operations and the high-speed train makes it quicker to go from Paris to Marseilles than from London to just about anywhere north of Birmingham, France is a country to be envied, not sniped at? What if, while retaining a quality of life that is all their own, the French have managed to meld an abiding sense of national identity with an ability to have the best of most worlds? What if, for all the excessive power of their state, they have been rather more successful than us at merging the public and the private in everything from motorways and aeroplanes to preserving a national film industry?

Even worse, what if they couldn't care less about what we say, knowing that, for all the broadsides and professions of superiority from this side of the Channel, the traffic still runs south? In which case, the attitude of George III and his distant relation become easier to understand. Sadly for us.

Jonathan Fenby's On the Brink: the trouble with France is published by Warner Books (£9.99)