Labour is set to slash a ‘hidden tax’ on gas boilers that was introduced as part of the UK’s drive towards ‘net zero’ carbon emissions.

Controversial policies created by the Conservative government would see boilermakers fined if they fail to meet targets for selling heat pumps. Manufacturers have said they would have to increase the price of boilers by at least £120 to cover the cost of the penalties.

The previous government delayed the implementation of the fines – which meant the can was…