The onslaught began last week when Tory MP Patrick Mercer branded Tesco and Asda "immoral and irresponsible" for selling alcohol below cost.
Addressing MPs on the Home Affairs Select Committee, Asda head of licensing Rob Chester admitted that Asda did sell below cost on occasion, but that most of its customers drank responsibly.
MPs were told that a large percentage of young people used cheap supermarket
alcohol to 'pre-load' before heading out to clubs and pubs.
Meanwhile, independent retailer Chris Ray, who owns Pound Road Stores in Bristol, has written to Asda chief executive Andy Bond, complaining of a promotion that it had run on Blackthorn cider.
Asda had been selling packs of 18 x 440ml cans for £8. Chris referred to his most recent invoice from a well-known wholesaler where he had paid £11.49 to buy the same product.
The deal also coincided with the last day of term for many school leavers. "To run the ad then suggests a serious failure on the part of your people," Chris wrote.