A generation of Birmingham youngsters face a health timebomb because of the availability of cheap and strong alcohol, health officials have warned.

It has become a city of "stay-at-home drinkers" who have no idea how much damage they are doing to their livers, according to a new study.

More women are showing signs of liver disease and children run the risk of major health problems in adulthood as they start "dabbling" with alcohol from the age of 12.

The warnings came from liver experts at Queen Elizabeth Hospital in Edgbaston who carried out random tests in the city centre as part of a Channel 4 Dispatches documentary being broadcast tonight.

Dr Andy Holt, a specialist registrar at the QE's liver transplant unit, one of the largest in Europe, thought about five per cent of those tested would have above normal readings.

But of the 45 people in Birmingham who agreed to a blood test for two enzymes produced when the liver is not working properly, 25 individuals (55 per cent) produced "worrying readings". Levels of alanine aminotransferase (ALT) should be less than 41 for men and under 32 for women, while gamma-glutamyl transferase (GGT) readings should be between 11 and 50 for men, and seven to 32 for women.

Dr Holt, who carried out liver scans in Victoria Square in April, said: "As a yardstick, these results are really quite shocking.

"Also many of the people I spoke to seemed to have no idea about how much they drank until they totted it up day by day. People counted drinks rather than units, so if a guy drank 10 pints over a weekend he equated it to that instead of the 20-plus units in those pints, which puts him well above the recommended eight units a week.

"There does appear to be a clear correlation between the availability of alcohol and the prevalence of liver disease in the UK."

The impact of Birmingham's drinking culture is taking its toll on the population.

Surgeons at the QE's renal unit carry out about 150 liver transplants a year, but demand always outstrips supply and not all patients waiting for a new liver survive.

Dr Holt added: "We're seeing more cases of liver disease in patients in their 30s, particularly young women, and that's borne out by the number of women we tested who drank regularly. Children are starting to dabble with alcohol from 12 and 13-years-old, and if cheap, strong alcohol is available they will drink it.

"However the truth is we will not see the impact of this for another 10 or 15 years, when their livers will be severely damaged if they continue to drink at such levels."

Researchers found more people in Birmingham, compared with the London group, drank at home, often buying their wine or beer at supermarkets.

Among the "stay-at-home drinkers" was Bromsgrove Tory MP Julie Kirkbride, one of three politicians out of the 200 invited who had their livers scanned at Westminster.

The programme shows Ms Kirkbride punching the air when she sees the results, before confessing to being "a bit naughtier" than the Government levels recommend.

"I can't tell you how relieved I am as I'm a bit naughtier than all those guidelines suggest," she said. "I'm not a binge drinker or anything like that but my husband and I do split a bottle of wine between us most nights.

Deborah Davies, a Dispatches reporter, said supermarkets had to take some of the blame for their cut-price drinks promotions.

She said: "We got a real mix of shoppers, office workers, passers-by and students in Birmingham, most of which drank mainly at home, and mainly supermarket wine often bought as part of a special offer.

"More than 60 per cent fell into that category, who admitted drinking 'a couple of glasses' of wine every night, and without them realising they've put themselves above the risk levels recently set by the Government.

"Anything over six units for women and eight for men puts them 'at risk', but a 250ml large glass of red wine contains 3.5 units."

"The Government is to hold an inquiry next year into whether supermarket prices and marketing are leading to people drinking irresponsibly. But it will take years and years to change the drinking habits that are inherent in this country."

* Dispatches: Drinking Yourself To Death is on Channel 4 tonight at 8pm.