Sushi, the former symbol of yuppie status, has finally come down to earth: it’s become so mass market it’s going on sale at holiday camps.

The little parcels of rice and fish, once the preserve of rich bankers paying £50 a plate, are being served up at Butlins in Bognor Regis. Forget the traditional fish and chips – yesterday’s “hi-de-hi” arrivals were being tempted with platters of 10 sushi pieces at £7.95 a go.

The move reflects the remarkable evolution of sushi, which has gone from culinary speciality to mass market success faster than most cuisine. However, environmental groups now fear that growing demand for the dishes is compounding the pressures on stocks of rare fish such as the bluefin tuna.

David Ritter, senior oceans campaigner for Greenpeace UK, said: “In terms of rarity, eating bluefin tuna sushi is no different to eating rhinoceros.” The fatty underbelly of the bluefin has become the Japanese equivalent of caviar. This autumn Greenpeace will mount a campaign against restaurants and chefs in Britain who do not use fish from “ethical” sources.

At the same time, however, sushi’s very success has corrupted its style and content in the West. The cuisine dates back almost 2,000 years to when raw fish was packed between layers of rice as a way of preserving it. The traditional Japanese way of making the dishes was largely supplanted soon after they were introduced to the wider market.

Simon Woodroffe, the former Rod Stewart roadie who founded the Yo! Sushi restaurant chain with £150,000 in 1997, said: “The worst corruption of sushi I have seen is probably by me. When we opened I said to the chefs: do anything you like that you think feels Japanesey.

“At the beginning we did dynamite rolls with chilli, Philadelphia rolls with cream cheese and something called ‘roll over Beethoven’, but we came back to the standard dishes. It’s like fashion – if you go back to the classics you always win in the end.

“The rave generation grew up, got married and now wants to go out to eat and there is a sophistication about them. They want to eat sushi and do the cool things.”

Woodroffe sold most of his stake in Yo! Sushi for £10m in 2003, but still has an interest and the company, which serves 3m customers a year, will soon open its 60th restaurant. There are now about 350 sushi restaurants in Britain, and the swankiest, Nobu London, part-owned by Robert De Niro, has a lengthy waiting list for tables.

Caroline Bennett, the managing director of Moshi Moshi, which introduced the first sushi conveyor belt to Britain at its restaurant inside London’s Liverpool Street station in 1994, said: “Once it was only served in very expensive Japanese restaurants catering for Japanese bankers in London. The conveyor belt has broadened it to a wider audience.”

In supermarkets, sales of sushi have risen by 30% in each of the past two years. A company called Taiko Foods uses 25 tons of rice a week preparing sushi for supermarkets such as Sainsbury’s, Tesco, Morrisons and Waitrose and high street outlets like Boots and Pret a Manger.

Its sales manager, Derek Lewis, said: “Sushi is now an attraction to all types, from the City gent to the white van man. But you can’t put things out there that scare people. The majority want simple sushi.”

Butlins is taking a similar view: it will include raw British salmon in its sushi but will cook the tuna used.

“It’s cheating a little bit, but at the end of the day we know what our customers like,” said a spokeswoman. “We want them to be comfortable with it and to give the healthy option a try.”

David Lancaster, the food writer and founder of Restaurant magazine, is philosophical about sushi’s conveyor-belt journey from speciality to mass market.

“We take foreign foods and we always anglicise them to a degree,” he said. “We have done the same with Indian and Italian food. We are more absorbing of them than other countries.

“You can either say sushi has gone downmarket or you can say it’s got more democratic with chains like Yo! Sushi. It’s a good thing that it is on the menu at Butlins. It’s probably better than what they were serving before.”

Sushi purists, however, may be aghast at some of the latest developments. A few “fusion” restaurants now offer deep fried sushi, and a US company is making a product with rice, tuna and salmon, designed to look and smell like sushi . . . for pets.

The 2000-year-old fast food

While forms of sushi date back 2,000 years, the familiar dish of raw fish and rice we know today was invented by Hanaya Yohei in Tokyo in the early 1700s. Breaking with the tradition of fermenting the fish together with rice, Hanaya came up with a quickly prepared food that people could eat with their hands at the roadside and opened his Yohei Sushi shop.

Britain now munches its way through £500m of sushi a year. In Japan aficionados of “extreme sushi” eat 10,000 tons of puffer fish, which contains tetrodotoxin, one of the most violent poisons found in nature. About 70 people die a year from its poison.

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