Ella is 20. She is amazingly beautiful, with hair like Jane Fonda's in Klute and the sweetest face. Her cheeks are flushed candy pink, like her dress, and though her feet are still, her body dances to the music crashing through the upstairs bar of the Lock Tavern in Camden, north London. In her hand she cradles a glass of Jack Daniels and Coke. It is her fifth of the evening and the night has hardly begun.

Ella doesn't know it, but she - like any number of young women out on the town at weekends - is at the centre of a growing panic about girls and booze. Along with tens of thousands of others - both women and men - Ella is a classic British binge-drinker. She abstains all week, and then on Friday and Saturday puts away more alcohol in a couple of heavy sessions than most women elsewhere in Europe will drink in a month. And as the party season gets under way, it's likely to get worse.

Ella started experimenting with alcohol when she was just 11 or 12. Her mum and dad had split up, and her older sisters would take her out drinking. "I used to get completely out of my head. I would drink all day, and, yeah, sometimes I couldn't remember what had happened," she says. One night a boy stole £300 from her when she was too drunk to stop him. "That made me feel awful."

Nowadays she takes care to pace herself. She rarely drinks during the week because she has to get up for work and is ambitious to do well, so her drinking is confined to the weekend. She drinks enough to make her feel "merry", but not so much that she forgets where she has been or what she has done. But she admits it takes more to make her merry than it once did. "I'm much better now. If I do get drunk, I'm always with a group of friends, so someone will watch out for me," she says.

We have always been big on binge-drinking in this country. But what is new is the number of young women at it. Men are still the worst culprits by far, but over the past 30 years, while men's drinking has remained largely stable, researchers have watched a steady increase in women's drinking, particularly among 16- to 24-year-olds, where the numbers have shot up rapidly. More than half of women aged 16 to 24 drink more than the amount deemed safe every week. Few know what the safe limit is (for women, no more than two or three units of alcohol a day, for men three or four); and even if they do know how many units, they have little idea what that means. (A pint of ordinary lager is two units; a bottle of wine is nine, an average glass of wine in a bar will be two units, and an alcopop 1.5.)

Binge-drinking is a peculiarly British problem. In wine-drinking countries such as France and Spain, where getting drunk is far less acceptable, people drink smaller amounts more regularly - the liver still suffers horribly because it never has a chance to recover from the steady drip of Beaujolais Nouveau - but they see fewer of the anti-social consequences. One rarely sees girls vomiting in the streets of Dijon, for example.

Not only do young British women binge, but they also drink more than women in any other European country. The average 18- to 24-year-old downs 203 litres of alcohol a year, the equivalent of more than five bottles of wine a week. Young Italian women, by comparison, manage just 59 litres a year, or one-and-a-half bottles of wine a week. And the results are beginning to show. There has been a rise in the number of women seeking help for alcohol problems - with equal numbers of men and women now wanting treatment.

Liver disease among women has risen dramatically. Over the past 20 years there has been a sevenfold increase in the number of women dying from the condition. It is not just older women who are affected. Last year, 300 women aged between 25 and 44 died of cirrhosis, compared with 500 men. Binge-drinking, combined with smoking, has also been blamed for an alarming increase in the incidence of mouth cancer in young women, with a 47% leap between 1990 and 1999 in the number of women under 45 affected, with some as young as 19.

Then there are the increased risks of breast cancer, reduced fertility, high blood pressure - which can lead to heart attack or stroke - weight gain, osteoporosis, loss of cognitive function, stomach inflammation and bleeding related to heavy drinking (at least 60 illnesses can be linked to it). Then there is foetal alcohol syndrome - when drinking during pregnancy causes damage to the foetus - the risks of unplanned pregnancy, HIV and rape.

Traditionally, women's drinking has followed a predictable pattern. After the student party years, consumption generally tailed off once they settled down and had children. Nowadays however, with women beginning to drink at a younger age (almost half of all 15-year-olds admit drinking), and settling down later, that drinking window has extended. Even once they are settled, professional women are less likely to cut back on their drinking, as the chances are they will have the opportunities and money to carry on.

But it is younger women's drinking that is currently the focus of concern. We have all seen the pictures; sunburnt girls vomiting and flashing their breasts in the Greek resort of Faliraki; groups of young women shouting and falling over in the street, Bacardi Breezers in hand. And we have seen the censorious media coverage - the Daily Mail's disapproval of hard-drinking, independent young women such as Zoë Ball and Sara Cox, and the condemnation of "ladette" culture.

"People don't like to see young women drunk," says Moira Plant, professor of alcohol studies at the University of the West of England. "Women have never been allowed to use alcohol in the same way as men. They are judged far more harshly."

People are genuinely shocked, she says, by the new visibility of drunken young women. "Young women are acting in the same way young men did 10 years ago - going out in groups, being noisy, aggressive, flirtatious. But women are no more stupid about their drinking than men. It's just we tend to judge them by a different yardstick."

So why are we drinking more? The most commonly offered explanation is women's liberation. With greater equality in the workplace, increased affluence and independence has come a greater appetite for booze and the feeling, well, the boys can do it, why can't we? Drugs are no longer quite as popular. And as women have taken top jobs working alongside men, not only have they had to socialise (ie drink) with their male counterparts to keep up, they have also turned to alcohol to help them deal with stress.

"In any job in this country, you are under some kind of pressure," says Plant. "Alcohol is used as a way to reduce stress. The risk with that is if alcohol is the only way someone knows how to reduce stress."

Equality is good and right, says Professor Robin Touquet, a consultant in accident and emergency at St Mary's Hospital, Paddington, but the health consequences for women are grimmer than for men. When it comes to drinking, he says, women face a distinct disadvantage because alcohol does more damage more quickly. "Partly because women are smaller; partly because they have lower levels of alcohol dehydrogenase in their stomach linings, they absorb more alcohol than men. It means they are more vulnerable to liver disease.

"Alcohol is a drug like any other. In reasonable quantities it's enjoyable. It breaks down social barriers and it makes people relax. But single occasion risky drinking leads to accidents. Clearly women are vulnerable."

For feminists, there is something deeply patronising about the way women are discussed in the context of alcohol. Sandra is 35, unemployed, and in therapy to try to address her drinking. She wants to cut down, but hates being told what she can and cannot do. "Although the decision is mine, it just feels like I'm a little girl, being told I shouldn't drink. Women want to keep up with men and why not? I always used to have half a lager, now I drink in pints."

According to Dr Betsy Thom, reader in drugs and alcohol studies at Middlesex University, today's debate about women's drinking has changed little from the debates of the 19th and early 20th centuries. Essentially, what is different about men and women's drinking is that women - then as now - are seen as "the guardians of morality in society". So the way women's drinking is reported is not just to do with the facts and figures, but with notions of what is expected of women's roles.

What is very different today, however, is the context of that debate - female-friendly wine bars, massively increased availability of alcohol in supermarkets, and targeting of women by the drinks industry with ready-mixed, low-cal girly drinks. "The industry must take some responsibility," says Geethika Jayatilaka of Alcohol Concern. "What they've seen is a whole new generation to target and they are going very heavily at them, with careful marketing and packaging of products aimed at women."

So what is to be done? We cannot turn the clock back. We cannot be un-emancipated, banished again to the kitchen and the occasional Babycham at Christmas. The government will next year implement its national alcohol strategy, which aims to address some of the more alarming trends, such as binge-drinking. But we know large-scale health education exercises don't work; and research in the US and Canada has shown that unit-labelling on bottles - another option under consideration - makes little difference. So what is the answer?

"People have to be responsible for how they behave, and to at least be armed with the facts," says Plant. "There are very few people who can drink very heavily and not come out scarred in some way at the end of it. My concern is that young women, who in general are very aware of their health and diet and count their calories, don't seem to see alcohol in the same way.

"I would like young women to be aware of what they are doing. I'm not saying don't do it. I don't have a right to say that." Indeed to do so only lays down a challenge to young women to behave even more outrageously than they might otherwise.

But don't we have a right to enjoy ourselves? We are all adults. It does not take a PhD in alcohol studies to understand that if you get outrageously drunk, you may end up in accident and emergency, and if you drink a lot, a lot of the time, you'll wreck your liver, just the same as any man.

Back at the Lock Tavern, Ella and her friend are off clubbing. Downstairs, Sarah Shebbeare, 20, a history of art student at University College, London, is making her bottle of beer last. She spent her early life in France where everyone grows up drinking a glass of wine with the family, but not much more. "I'm shocked by what I see at university. There's this night called sports night every week and people get drunk until they're sick back into the jugs they've been drinking from. It's very sad that people have to do it to have a good time."

Fiona, a 23-year-old Cambridge graduate, is celebrating a new job at a table nearby. She's careful about what she drinks - a few glasses of wine at the weekend. "I think there's a lot of scaremongering. Yes, young women are drinking more. They're much more up for going out on their own. We don't have any responsibilities at the moment. Also to stay in high-powered jobs, you have to socialise and a lot of that revolves around drinking. Equality between men and women is going to bring all sorts of things up. We want the things men have got, like the best jobs, but we don't necessarily want the things that come with them, like the consequences of heavy drinking."