One of the wealthiest entrepreneurs in Italy has championed the lot of tourists by expressing “indignation” over the “excessive” prices charged at cafés and restaurants in Venice.

Renzo Rosso, the unconventional self-made founder and sole owner of Diesel, the fashion label, said that his growing irritation turned to wrath when he took his wife, Erica, and their three children — Asia, Luna and India — to Caffè Florian, one of the most celebrated historic landmarks in the city, on St Mark’s Square.

Mr Rosso, 52, who comes from near-by Padua, said that they had enjoyed the orchestra that plays at Florian’s but had been stunned when they found that the bill included an extra charge of €5.80 (£3.90) a head for “musical entertainment”. “My wife and I had a spritzer each, for which the charge was €22,” he told Il Giornale. The price of the drinks was steep enough on its own, “but it’s the music charge that scandalises me most of all”, he said.

Mr Rosso, 52 — a farmer’s son who studied textile technology before creating not only Diesel but also, with the Genius Group, the labels Katharine Hamnett, Goldie, Martin Guy and Ten Big Boys — admitted that he could afford to pay. Diesel, an internationally recognised brand, has an annual turnover of £600 million and has 220 shops in 80 countries. But he said that cafés in Venice should offer entertainment free of charge. “At least I didn’t have have to pay for the children — otherwise I would have paid a total supplement of €29.”

Carlo De Pari, the manager of Florian’s — founded in the 18th century and frequented over the years by luminaries such as Casanova, Lord Byron, Marcel Proust and Henry James — said that the musical supplement had been added to the bill for many years. He said that the supplement was indicated on the menu and waiters were instructed to draw the attention of customers to it.

Mr Rosso’s protest comes as the Venice council — with the aid of the police — is cracking down on tourists who picnic on or near St Mark’s Square, with on-the-spot fines of €25 for those caught eating takeaway food. Many visitors complain that they have no choice, in view of the “astronomical” prices charged by cafés or restaurants, with or without music.

“Decorum hostesses” have been hired by the council to approach offenders and try “moral suasion” to stop tourists not only eating takeaways but also sunbathing and (in the case of men) stripping to the waist. “Napoleon called St Mark’s Square the drawing room of Europe,” said Augusto Salvadori, the Venice councillor in charge of tourism and decorum. “People must behave with respect.”

If “moral suasion” fails, the hostesses call the police. “We only intervene in extreme cases, such as when visitors turn nasty and assault the girls,” one policeman said. “You won’t believe this, but some people even get out portable stoves and start cooking.”

Setrak Tokatzian, deputy head of the St Mark’s Square traders’ association, said that the “decorum rules” were “demagogic”. Mr De Pari said that prices were likely to rise further at Florian’s next year to help the café to pay the fee charged by the Venice council for the “public space” on the square that it uses for its tables and chairs and the orchestra platform.

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