It is one of the pillars of the French "exception culturelle": haute cuisine so lofty that the president, Nicolas Sarkozy, wanted the United Nations to declare it a "world treasure". Those perfidious Rosbifs could attack their language and buy up half the Dordogne but they could never compete in the kitchen, declared the Gallic gods of gastronomy.

But a poll has undermined France's reputation as the home of unrivalled culinary excellence with results that suggest the British cook more often, for longer, and produce greater variety than their French counterparts.

As the French television station TF1 put it: "They trounced us at Trafalgar. They whipped us at Waterloo. Now the English have scored their ultimate victory: they are better at cooking than us … we, the self-proclaimed kings of nosh."

The survey, carried out by the French magazine Madame Le Figaro and the BBC's food magazine Olive, has produced an agony of French soul-searching – and a certain amount of disbelief – over the apparent erosion of the country's most celebrated heritage.

More than 2,000 French people and nearly 1,350 Britons were asked about their eating and cooking habits. Their answers revealed that 72% of the British cook at home daily, compared with 59% of the French. One British cook in two spends more than 30 minutes preparing a meal while only a quarter of the French spend that long.

Four per cent of the French polled admitted they never cook, four times as many as Britons questioned. While French and British cooks are just as likely to bake a cake or fillet a fish, nearly twice as many British people as French make their own bread.

Grandmother Marylene Gaggioli, 60, from Corsica, who has three daughters, said: "French women don't cook as much as they used to during the week because they work more and don't have the time.

"They freeze a lot more or serve ready-cooked things instead of serving something freshly prepared and made from scratch. It's just not the same. But many of them, like my friends who work, make up for it at the weekend when they have more time."

One of Gaggioli's daughters, Marilyn Jarman, 36, a French marketing manager, has lived in London for 15 years and admitted she had noticed a huge improvement in British food.

"When I first arrived in Britain, chicken kiev was about as adventurous as it got. Now there are farmers' markets and gastro pubs and we eat really well.

"French food is good but it tends to be very traditional and the same. My mother's a great cook but it's always the same dishes: sautéed veal, wild boar stew, cannelloni with cheese, fish soup."

Jean-Christophe Slowik, a French chef who runs L'Absinthe in Primrose Hill, north London, was deeply sceptical about reading the last rites to French gastronomy. "Maybe people in Paris don't cook much, but when I go to the French country cooking is still at the heart of French daily life," he said.

"If I'm there with friends we spend the morning talking about the meal we'll make for lunch and the afternoon talking about the meal we'll cook for dinner and the evening talking about what we'll do the next day. We French talk about food and drink and you British talk about business and property."

Lulu Grimes, food director at Olive magazine, said British cuisine had suffered from a postwar ready-made food boom but had improved enormously since the 1990s.

"The French have always been a bit sniffy about British food, thinking it came down to roast beef or nothing," she said.

Thierry Darras, responsible for the poll at Madame le Figaro, rejected outright any suggestion the British are better cooks than the French.

"They may spend more time than the French in the kitchen during the week but the findings were reversed at the weekend," he said.

"The interest in cooking in France has not lessened, it has changed. The savoir faire is still there and is being refined."

Asked what he thought of British food, Mr Darras did not mince his words. "I have not had many occasions to try it but I can say I am not a fan at all," he said. "It is not very refined."