The evidence base for the government’s alcohol minimum unit pricing plans was “shot down in flames” this week, drinks company bosses claimed, after researchers drastically scaled back their estimates for the impact on the nation’s health.

Claims that minimum pricing would save up to 2,000 lives a year were more than three times overestimated, researchers at Sheffield University admitted in a report on an update to its modelling.

The original study in November 2009, used by David Cameron to back minimum unit pricing, predicted the policy would prevent 344 alcohol-related deaths in its first year, rising to 2,000 by year 10. The updated report, published this week, revises that to 123 deaths in year one and 624 in year 10.

“This completely shoots down in flames the evidence the government used to back minimum unit pricing,” said a leading drinks industry source. “Ministers have obviously looked at these results and realised it just doesn’t stack up.”

Dr John Holmes, of the University of Sheffield, said the change in the figures was down to improved modelling, including updated population and inflation rates.

The new report also found the impact of 45p per unit MUP plans would have had a much smaller impact on consumption than claimed. Consumption would reduce by 1.6% rather than the 4.3% forecast in 2009, it found.

This week, a string of NGOs, including Cancer Research UK and the UK Health Forum, quit the Responsibility Deal alcohol network in protest at the government’s decision to abandon MUP.