Huge numbers of young people are now downing alcohol at home before they hit the pub, according to research.
More than eight out of 10 (83 per cent) people are now indulging in the phenomenon - known as 'pre-loading' - with many of them drinking three drinks or more when they do.
And the Galaxy Night Out survey from licensed trade research house CGA has blown a hole in claims from supermarkets that bargain-basement off-licence deals are not fuelling binge-drinking.
Two out of three people say they consume shop-bought alcohol either immediately or over the course of a weekend - up from 56 per cent when a similar survey was carried out two years ago.
Seven out of 10 meanwhile say in-store promotions such as 'buy 2 get 1' free entice them to purchase more alcohol than they normally would.
Graham Pitts, account manager at CGA, said: "The long-term effects on the health of young people who drink in this way are potential headaches for our industry - we'll see more legislation, more negative mainstream press coverage and more calls for restriction.
"Will alcohol become the new tobacco? There's a chance, unless our industry and government stop irresponsible off-trade retailers being sick outside the on-trade's front door."
Danny Scott, licensee of Rick's bar in Greenwich, South London, said this practice makes life more difficult for barstaff.
"You see it more with younger people, especially when they're going out for a long night," he said. "But if someone comes out of my door drunk, people assume he got drunk here. We're tending to take the blame for something that's not our fault."
The major retailers have repeatedly stood by their alcohol deals, with Sainsbury's head of legal affairs Nick Grant describing claims binge-drinkers stocked up with cheap booze from supermarkets as "complete nonsense" at a meeting with MPs in April.
Key findings
• 83 per cent start drinking at home before going out
• 22 per cent down between three and five drinks before going out
• 42 per cent consume more than 11 drinks per week
• 70 per cent said in-store promotions such as buy 2 get 1 free encourage them to purchase more alcohol
The sample of 1,886 people was taken from Leeds, Sheffield, Hull, Manchester, Newcastle and Birmingham. Fifty-seven per cent were aged 18 to 24, 27 per cent were 25 to 34, with 10 per cent 35 or older.