Households living in nearly 1 million homes built since 2015 have been hit by an additional “energy bill bombshell” totalling ￡1.8bn because of the government’s decision to scrap net-zero targets, Liberal Democrats have said.

       And the average ￡200-a-year cost for each household is due to soar higher over the coming year, following the massive hike in the energy price cap in April, which is expected to be repeated in the autumn.

       Laws passed under the coalition government to require every new-build home to have zero carbon emissions were scrapped by David Cameron’s administration soon after Conservatives took sole control in 2015.

       Since this time, almost 1m homes which do not meet zero-carbon standards have been built.

       Lib Dem climate emergency spokesperson Wera Hobhouse said that the “abysmally short-sighted” decision will have pushed many families towards fuel poverty as the price of gas and electricity increased by an average ￡700 earlier this month.

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       The party is putting cost-of-living concerns at the heart of its campaign for local elections across Britain on 5 May.

       Figures from the Energy and Climate Intelligence Unit (ECIU) suggest that measures to make homes zero-carbon typically save households around ￡200 a year on their energy bills, thanks to factors like better insulation.

       Over the seven years since the policy was scrapped, the total extra cost in bills is estimated to have reached ￡1.8bn and the figure is climbing ever-faster.

       “Families up and down the country are being driven into fuel poverty, having to make agonising choices between heating and eating because of the Conservatives’ cost of living crisis,” said Ms Hobhouse. “This pain and misery for millions had been coming down the track for a long time. Scrapping zero carbon homes has proven to be an abysmally short-sighted move from a government that has failed with all hands to protect people from sky-high energy bills.

       “New homeowners can send the Conservatives a message in May by voting for your local Liberal Democrat champion. They have failed families struggling with their energy bills and it’s time to send them a message.”

       Ms Hobhouse’s party is calling for a windfall tax on energy firms to pay for measures to reduce energy poverty and insulate homes.