Suppliers should treat customers with compassion, an Ofgem spokesperson said, adding that it was keeping standing charges under review.

Energy UK said suppliers had increased support “during a very difficult time for its customers over the last 18 months”.

This includes “emergency credit, offers of payment holidays and altered repayment arrangements”.

Customers may also be able to get direct financial assistance through suppliers’ funds, “which are often run in partnership with charities and consumer groups who can also offer specialist support and advice”, a spokesperson said.

“An extended period of record bills has seen an unprecedented number of customers seeking support with call volumes quadrupling and an accompanying increase in the time taken to resolve challenging and complex cases,” the spokesperson added.

So energy firms have expanded customer service teams and set up specialist teams “to deal with the most challenging cases”.

“Suppliers will continue to do all they can to support customers struggling with bills but in the middle of a wider cost-of-living and affordability crisis, they alone cannot provide all the help people need,” the spokesperson said.

Mark Garnier, who is also on the MP committee, said that while the government “did step up to the plate last year” it now “needs to give some assurances on support to vulnerable households”.