Slabs of cloud were turning pink in the sky and a fleet of stretch limousines and Humvees waited in the car park. Inside the country club, in dinner jackets and prom dresses, the class of 2008 were acting out an American rite of passage.

It might have been a scene from a high-school drama, except that it was happening in Chigwell, Essex. Nor was the Chingford Foundation School prom an isolated incident that night. Another prom was in full swing at a hotel three miles down the road. At the same time, Richard Turner, an events photographer, was taking pictures of prom pupils beside the pitch at Old Trafford in Manchester, after a week spent tearing up and down the country from prom to prom.

Event photographers are unable to cope with the demand. Ricky Turrell, a photographer in the South East, had 36 requests from schools holding postproms next Friday, the peak day in Britain’s new postGCSE prom season. Beauty salons are fully booked and there is a shortage of limousines.

Schools that once had a “leavers’ disco” in the gymnasium, – events characterised by intense social awkwardness – are now throwing ever more elaborate prom parties demanded by a generation who have grown up watching American high-school dramas.

Kate Sawyer, 56, one of the pioneers of the British prom, told The Times: “It’s the American influence, and it’s a good excuse to put on a posh outfit.”

Her school, Furtherwick Park, was the first in Canvey Island, Essex, to develop a prom tradition and the first to move the event to a venue outside the school grounds. “The boys look like ushers at a wedding,” she said. “The girls look like bridesmaids. Outside school you are used to seeing them in their hoodies and jeans round their bottoms.” She hardly recognises them.

“Everyone wants to dress up and look wonderful once in their life,” she said. “For most girls it would have been their wedding day. Now it’s another occasion. Girls are getting married later or not at all.”

Two years ago her colleague Dawn Theopos hired a dress for her eldest daughter at a cost of £75. Proms have grown since then. “This year my youngest daughter had her prom dress made,” she said. “It cost £650. I have never spent that much money on a dress in my life.”

Not everyone is delighted by the arrival of the prom. “It is an unnecessary American import and any self-respecting government would ban it,” an anonymous teacher from North Wales wrote on an education website. “When the fateful day arrives, there is no hope of teaching anything at all. After all, Year 11 are to be found elsewhere: the beauty salons and hairdressers. Hair like plywood, eyelashes like birds of prey and faces like plates.”

Gerald Haigh, a former primary school head teacher, worries that “families get railroaded into it when they can’t afford it”. Last year he voiced fears that the prom was spreading to primary schools: a friend had informed him of a Year 6 leaving party where “he’d counted four stretch Lincolns, two stretch Hummers, assorted Jags, Beemers and Mercs, all queuing to drop off their cargoes of buffed sprogs and sprogettes”.

Carl Westwood, the head of LA Limos in London, says that he now takes regular bookings from schools, for arriving is a crucial component of the British prom. Mr Turner, the photographer, has seen fire engines and fleets of Minis styled afterThe Italian Job. At Ryburn Valley High School prom in May, three dinner-jacketed students arrived in a helicopter.

The Times attended the Chingford Foundation School Prom and arrived in a taxi without a date, feeling underdressed. Chase Griffin, 16, in an elegant charcoal suit (Topman, £160), and with a new hair cut, explained the significance of the prom. “Sex!” whispered an excitable boy beside him. “No, it’s about saying goodbye to people,” he said. “Our parents love it when we get dressed up.”

Rory Carter, the PE teacher and head of year, was giving out prizes in the ballroom below. “Best-dressed female,” he cried. “This one is very difficult.” “Miss Hines! Miss Hines!” came the shout from the dance floor.

“I said best, not worst,” “Coach” Carter said. “The award goes to . . . Charlotte Mooney.” Miss Mooney stepped up to receive it in a sequinned turquoise gown, bought for £150 in Finsbury Park. A girl named April felt rather aggrieved. “Oh, sorry, April,” Coach Carter said. “She’s in the same dress! She wins too.”

A confident young man named Harrison was voted “person most likely to succeed”. “Thank you to everyone,” he said. “It’s been the best five years of my life.”

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