Millions of customers could be set to see their fuel suppliers go bust amid the ongoing energy crisis. 

Chief Executive of Ofgem Jonathan Brearley told MPs this morning that "well above" hundreds of thousands of people may be affected in the coming months. 

The energy watchdog chief refused to give a more specific estimate of how many people could be left in limbo when he appeare at the Business, Energy and Industrial Strategy committee. 

He said: “We do expect a large number of customers to be affected, we’ve already seen hundreds of thousands of customers affected, that may well go well above that.

“It’s very hard for me to put a figure on it.”

However Conservative MP Alex Stafford challenged the regulator, saying:"You said a large number of customers, more than hundreds of thousands...So I take that in millions. You may not be able to say more than that, but that's what I'm reading."

Mr Brearley replied:"I think, certainly a large number of customers" but added he did not want to "preempt" any "commercial conversations" currently taking place.

The UK Government has been in talks with industry suppliers and Ofgem in recent days, following the surge in gas price  and the closure of two plants that produce CO2 essential for the food processing industry, among others. 

A deal has been struck with the CO2 fertiliser plant bosses to ensure it resumes operations, amid fears that meat, vegetables and frozen products would soon be in short supply.

However discussions are still ongoing with energy companies after a number went bust in the past few weeks, and others look likely to be on the verge of collapse. 

Emma Pinchbeck, head of the trade body Energy UK, told MPs that it was not the case that firms were going bust due to being poorly managed.

She also revealed that the Government and Ofgem were warned two years ago about problems with the energy retail market. 

Ms Pinchbeck said: "I took this job a year ago. When I was hired, the chairman of Energy UK said that your biggest challenge is going to be the vulnerability of the retail market.

“I know that for a year or more before that my team have been making the case to the regulator and the Government that the sector is fragile.”

“A lot of that is about market design. No competitive market would be making an average return of minus 1%."

She told MPs that the current problem of soaring gas prices may be "short term" but it has only made issues for the sector worse, and was not the sole cause of suppliers going bust.

She explained: "There’s a short-term crisis here, which is in some ways out of our control, it’s to do with the gas prices, but it’s been exacerbated and arguably caused by our regulatory design.

“That is a resilience and security of supply risk in the future. It’s terrible news for customers in the long run.

“When we get through this, whatever support we put in place in the short term to make sure that customers are looked after, we desperately need to stop dismissing retailers when they say the market design is not fit for purpose, the market design is harming customers, the market design means we’re not making any margin and the market design leaves us vulnerable and fragile.”