The government’s plans for minimum pricing of alcohol are badly targeted and would hit poor families the hardest, according to new research.

A report by the Centre for Economics and Business Research, commissioned by SABMiller, describes the plans as “highly regressive” and said they would have a greater impact on the expenditure of the poorest 20% of households in the country.

“A minimum unit alcohol price of 45p has a negligible impact on hazardous and harmful drinking levels among the richest 20 % of households in the UK,” the CEBR said.

“We estimate that Yorkshire and the Humber would be the region hardest hit by minimum unit pricing, in terms of the increase in alcohol expenditure that the average household would face under the policy. A 45p minimum unit price would lead to the average household in Yorkshire and the Humber spending an additional £49.22 per annum on alcohol products.”

The news follows weekend reports suggesting that David Cameron is facing growing opposition from Conservative and Liberal Democrat MPs worried about the economic impact of the plans.