Several boiler manufacturers, including Baxi and Worcester Bosch, have announced the introduction of a 'CHMM levy' on residential gas boilers delivered from 1 January 2024.

Baxi says the levy is not a price increase, but a direct impact of the CHMM on its business, which it will use as payment to the government for the penalty they award for not meeting its 4% target (under CHMM).

In an interview with LBC, Ms Coutinho said these proposed price increases were an example of "price gouging plain, and simple."

She added: "What we have at the moment we have a policy in place where they have to sell 4% of their boilers as heat pumps.

"Industry estimates that the market overall is selling 4% at the moment. We think it's extremely unlikely that anyone will be fined. They say they are going to put £125 on boilers because they are expecting to face the full fine.

"So, I do think it's something I'm going to look at very carefully. And I will talk to anyone who I believe is passing on unfair costs to the consumer."

In an interview with Sky News, Worcester Bosch CEO Carl Arntzen, explained why the company moved to introduce the CHMM levy. He said: "We're applying this levy outside of any VAT or tax implications, so this is purely an additional cost on the boiler, that we will not make profit from. We are purely and simply using that levy to pay the fine we believe we will have to pay next year.

"For the whole industry, it is a huge threat to our existence moving forward. We accept we have a responsibility to grow the market for heat pumps, equally the government has a responsibility to assist in growing that market."