Consumer champion Martin Lewis has apologised for swearing to Ofgem staff as he condemned proposed changes to the energy price cap.
The energy watchdog on Monday said they are considering reviewing the price cap, which regulates bills for 23 million households, every three months instead of six.
The change would result in more frequent changes to customers' monthly outgoings in a bid to make bills more reflective of fluctuating wholesale gas prices.
Lewis apologised on Twitter for an outburst during a briefing on the changes.
He wrote: "I'd like to formally apologise to the Ofgem staff for losing my rag in a background briefing just now and saying its changes are a "f***ing disgrace that sells consumers down the river.
"I should've behaved better. My ire's institutional not individual, it was inappropriate.
"I lost it when getting a briefing about today's proposals, where it feels like at every turn, in these desperate times where lives are at risk, it has ignored all asks for consumers and instead kowtowed to the industry (I hope history proves me wrong)."
Other changes proposed by Ofgem could also result in energy companies less able to offer lower and more competitive prices due to changes to the market stabilisation charge.
The charge is a temporary measure that requires domestic suppliers who acquire a customer to pay a fee, which is then distributed to other companies that lose customers when wholesale prices fall below the wholesale price cap index.
It was introduced in April and is set to expire in September 2022.
"My breaking point was when hearing how instead of listening to calls to scrap its proposed market stabilisation charge, it was making it harsher to really 'stop the harmful effects of competition' i.e staggeringly its aim's to effectively STOP firms undercutting the price cap", said Lewis.
"Its logic was this would prevent other firms needing to 'exit the market'. For years I've been pushing it for better controls in who they allow to set up energy firms.
"Yet now its way to stop it is to lock in advantage to higher charging incumbent former monopoly firms".
Lewis added: "Its a disaster that means if wholesale prices fall and a new firm gets a switcher, it must pay 85% of difference to old firm. Killing hopes of firms launching cheaper deals."
Ofgem CEO Jonathan Brearley on Monday said energy bills would not be higher for consumers with a more frequent price cap review period.
"The total cost you pay over the year would be absolutely the same because that reflects only the cost of the energy that we buy," Brearley told Sky News.
"But again, the price would go up more quickly as prices go up. But equally importantly, as those prices come down the price comes back down again."
But he did concede the situation is set to get worse in the coming months.
“Things are going to get tougher as far as we can see, it’s not certain, the market is changing dramatically almost day by day," said Brearley.
"But we, you know, have to warn customers to expect further price rises in October.”
It comes as the government is under growing pressure to help Brits struggling most with soaring energy bills.
Rishi Sunak announced a partially repayable energy bill package of measures in February to ease the burden on households. The package comprised of:
£150 council tax rebate for council tax bands A-D
£200 discount on energy bills to repaid over five years in £40 instalments
However, while the government have staunchly defended the measures, the arrangement has been criticised for being partially repayable and not going far enough.
The Office for National Statistics (ONS) reported last month that 40% of Brits are now struggling to afford their energy bills.
Opposition parties are calling for a windfall tax on the unusually high profits of oil and gas companies who have seen a spike in their income due to the volatile energy market driving up prices. They argue the money could be used to provide greater and more targeted support to households on the lowest incomes.
Paul Johnson, director at the Institute for Fiscal Studies (IFS), told TalkTV on Monday that windfall taxes are not good for investment, but there was a strong case in this instance.
"Generally speaking, these ideas of windfall taxes aren't a great idea because you do create uncertainty for firms that are looking to invest and investment is a problem in the UK anyway," said Johnson.
"However, on this occasion, I think there is more of a case than perhaps there is normally".
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