The girls have got themselves ready for a big night out. There's Becka, Laurie, Corina and Jodie, who spent most of the afternoon at the hairdresser's getting herself dolled up for the occasion. Her hair is a glorious confection of platinum blonde curls, Sheffield's very own Marilyn Monroe, except that the original Marilyn probably did not have Jodie's thirst for Malibu and orange.

“I will probably have 15 of them,” she says with a half-serious smile, which suggests that she has been here before, and knows what she is talking about. “We will probably go on till three and then have a kebab.”

It is early yet; the pubs and clubs in West Street, a binge drinkers' paradise where every other bar has cheap drink promotions, are starting to fill. “That's why we are still looking nice,” says Becka, who has kicked off with a pitcher of Long Island iced tea. “My hair is still nice, my make-up is still on.” They seem engaging girls, fun and full of opinions, and far from stupid: but probably best met before kebab time.

The place where they are drinking, the Cavendish, has, like every other bar in the street, a sign outside advertising cheap drinks. Every night there is a different promotion, and tonight is Bulldozer Night, with a double vodka and Red Bull only £2. TVR is £2 too. This Times writer, being male, Southern, and middle-aged, has to ask at the bar what a TVR is: it's tequila, vodka and Red Bull. Does anyone ever pay full price?

Discount drink offers such as these are under threat of being banned by the Government when it announces regulations to deal with excessive drinking next week.

No more cheap TVRs, or two-for-one drink offers — 2-4-1s as the Sheffield shorthand has it — or any drink for £1, all of which was on offer in Sheffield this week. One bar owner even claimed that there were places selling drinks for 90p (there is always someone cheaper, somewhere, even if you can't find them).

Jodie, 19, who works as a manager in a Mexican restaurant — her friends work there with her, although Becka and Corina are also students — is in no doubt about her favourite promotion. “It's Vodka Revolution on Tuesday,” she says. “Tosser Tuesday — you flip a coin, and if you go heads and it comes up heads you get your round for free. I love it. I prefer to spend my money on my outfit than my drinks.”

In Sheffield, anyone seriously interested in discount drinking has plenty of opportunities. Down the road the Harley has a sign proclaiming: “The Art of Afternoon Drinking. Practised and Perfected in Sheffield. Every day until 9pm.”

There is Cusqueña bottled beer for £1.80, a large glass of wine for £2.90, and a double Bombay and tonic for £3. A group of nurses from the nearby hospital, exhausted at the end of their shift, are cackling with laughter over a much needed drink. They swear, absolutely swear, that they are only here for the one, and will be going home before long.

Back at the Cavendish, Rachel and her friend Jenny are as glamorous as anything South Yorkshire has to offer — Rachel in a black, one-shoulder dress, Jenny in a turquoise spangly number — “She looks like a mermaid!” says Rachel, hooting with laughter.

They have not been there long, and have already demolished their first bottle of Blossom Hill rosé. “It's £6.99,” says Rachel, 20, an office administrator and trainee accountant. That sounds cheap, but Rachel — a girl seemingly with her head screwed on, money-wise — is not impressed. “It's £5 in the shops.”

Rachel has been drinking since she was 15, back in the days when the pubs were pretty lax about the age rules, and knows all about what to expect from a big night out. “I would have a couple of drinks before I went out,” she says. “Then I would go out at about nine or ten, and then probably have a drink every other half hour, and maybe a couple of shots depending on what mood I'm in. I can go out and spend £80 on a night — £60 on drinks, £20 on taxis.

“It's not all drinks for me. I'm a bit too generous sometimes. Then it's, ‘Oh, all my money is gone, that's all right, I will get another 50 quid out.' Then at 3am you've got a group outside the club having a brawl, a lass with her friend being sick in the gutter, another lot having a fight about who was first in the taxi queue, and people having fights in the take-away.”

What is she like at the end of all that? “Very drunk.”

Curiously, and perhaps it is just because she has got a job, Rachel shows little interest in discount drinking. “People who go out for a cheap night, and take advantage of the offers — that's people who want to get absolutely rat-arsed.”

Perhaps the ones she is thinking of are at the Bedroom, a bar offering “2-4-1 pints and bottles” all night. As the music plays thumpingly loud — chugga-chugga — a group of lads are standing by one of the tables, indulging in what can only be described as a spectacular display of two-fisted drinking — Becks in one hand, Budweiser in the other. Barry's party trick is no-handed drinking, just a bottle clamped between his teeth and up-ended down his throat.

His friend, Johnny, 23, a demolition worker, rattles off the names of the local cheap bars. “The best prices are the Varsity, £1 a drink, and RSVP. Those are where all the birds go, where the cheap drinks are. Cheap drinks, birds.” He won't be getting drunk, though; it is Thursday night, and he has to work tomorrow. What does not getting drunk involve? How many drinks? “I don't know — 10 or 12, maybe.”

At midnight the street is swarming with young people, girls in miniskirts, boys in shirtsleeves, all oblivious to the near-freezing cold. A girl runs across the road, narrowly avoids being hit by a taxi and then collapses in a fit of giggles on the pavement. There is a long queue at the cash machine, but Rachel isn't among them; she is being sensible tonight. And anyway, tomorrow is another day.

A popular institution

— The term “happy hour” originated in America in the Twenties. It was US Navy slang for a theatrical performance that took place on board a ship. The “happy” referred to the state of inebriation usually associated with such shows

— During Prohibition in the US, when the sale and consumption of alcohol was banned from 1920 to 1933, the “happy hour” was a popular after-work event where people could have a sly drink before they went out for a meal

— “Happy hours” have been banned in the US state of Massachusetts since 1984 and the Republic of Ireland since 2003

— In the Netherlands, the price of alcoholic drinks is regulated by the Government and cannot be reduced, so many bars offer double-sized drinks during “happy hour”

— The Housemartins had a hit with the song Happy Hour in 1986

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