Supermarkets are cutting the price of beer to the equivalent of as little as 48p a pint.
Asda sold 24-can cases of Boddingtons bitter for £9 last week and offered the same deal on Blackthorn cider, which equates to 48p a pint - less than a fifth of what drinkers pay in a pub.
Tesco sold 24-can cases of branded beer for £10, or 54p a pint, while Sainsbury's sold 15-can cases of Foster's and Carling for £9, or 77p a pint.
Sainsbury's said both beers were on promotion for the Bank Holiday at £9, and were now selling for £11.
The average cost of a pub pint of Boddingtons costs £2.80, while Foster's sells for £2.90.
A spokesman for the British Beer and Pub Association said: "These bargain basement booze offers are irresponsible and indefensible. We call for the same robust action to be taken against the irresponsible promotion of alcohol by supermarkets as has been taken against pubs.
"The law now bans irresponsible promotions in pubs and, as we have consistently argued, the same should apply to supermarkets, which sell over two-thirds of the alcohol drunk in Britain."
But the British Retail Consortium (BRC) said supermarkets were not to blame for irresponsible drinking.
BRC director general Stephen Robertson said: "Promotions don't create excessive consumption. They simply offer customers value for money alongside other groceries.
"Irresponsible drinking is not about price, it's a cultural issue, as many police officers recognise. Alcohol is only occasionally sold at less than cost as part of promotions with manufacturers designed to encourage customers to try new brands. It is not the norm."