On a cold, foggy lunchtime in Turin, Demir Ergulu is slicing hot wedges of glistening meat into oven-fresh pitta bread as hungry office workers queue up. “This is local veal, bathed in milk and minced onion, then grilled with a touch of added veal fat,” said the Turkish kebab chef. “We don’t touch those frozen lumps of veal mixed with chicken and turkey that come in from Germany.”

Turin has backed Ergulu’s six-year experiment in gourmet kebabs, turning his kiosk into a cult address and a beacon for those who believe multiculturalism, starting with fusion food, has a chance in Italy. But as the country’s legal immigrant population swells to 7% it is touch and go, with anti-immigrant politicians on councils across Italy now seizing on the humble kebab as a symbol of the sort of cultural invasion they dislike.

Lucca in Tuscany set the ball rolling in January, followed by Altopascio nearby, where unknown assailants had already firebombed a kebab shop. Towns near Bergamo and Genoa followed suit, as did Prato in Tuscany, where 200 local people gathered this month to protest against the ban in the historic centre, not only of kebab shops, but also call centres and internet points, “all of which are, not by coincidence, managed by foreigners”, said protest organiser Marco Monzali.

An MP from the anti-immigration Northern League, which is behind many of the bans, forced French butter off the parliament’s restaurant menu, while police in Tuscany uprooted and seized unauthorised Chinese vegetables planted by Chinese immigrants.

Italy’s agriculture minister, Luca Zaia, a member of the Northern League, gave the raids his backing. “We must continue to block the arrival in this country of all foods which have nothing to do with our extremely rich agricultural heritage, and protect the hard work of our farmers and the health of Italians,” said Zaia.

“Where would Italy be today if the Northern League had been around to block the first imports into this country of tomatoes and potatoes?” asked culinary journalist Vittorio Castellani.

Following the summer’s kebab shop cull, Zaia did soften his tone. “We have nothing against the kebab,” he said, “but the frozen, imported ones are too much. Better to use Italian ingredients.”

Step forward Demir Ergulu, who was invited by Castellani to show off his all-Italian, fresh kebab meat stuffed into pitta bread, calzoni, focaccia and even spread on pizza with mozzarella at a food convention in Milan last week. Also on the bill was Sardinian chef Luigi Pomata, who opened a sushi bar in Cagliari using only Sardinian tuna. “When we started in 1996 we were discreetly mixing sushi dishes in with the usual Italian carpaccio – raw fish strips with lemon juice. Now Cagliari is awash with sushi bars,” he said. Moroccan chef Bouzhar Abderrahim, who studied in France and now works in Turin, uses couscous manufactured in Ferrara from local wheat. “Thanks to climate change, a lot of exotic foods are also about to become Italian,” said Castellani. “Okra is now grown in northern Italy and guava and lychees are produced in Sardinia.”

Councillors in Lucca insist that the last thing tourists want to see are wall-to-wall kebab shops. “Ideally we should be eating food grown on our own soil – that huge gastronomic resource everyone envies and which is the symbol of Italy around the world,” said Zaia.

But Castellani warned that xenophobic Italians were finding the defence of Italy’s culinary heritage a convenient cause to adopt. “If you go to the Facebook page ‘Yes to Polenta, No to Couscous’, you will find some violently racist comments,” he said.