Renewable energy provider Pure Planet is the latest to stop trading due to the soaring cost of gas.
A note on the firm's website said: "Pure Planet is ceasing to trade.
"Due to the global energy crisis, record high wholesale energy costs, and the restrictions placed on us by the Ofgem price cap, we are unable to keep operating Pure Planet. "
The supplier has 235,000 customers.
The energy price cap limits the amount firms can charge the average customer on their default gas and electricity tariffs - usually variable-rate deals.
But these providers are grappling with the soaring cost of gas - which currently costs five times its normal amount.
Are you a Pure Planet customer? Let us know in the comments below
Energy firms can't pass all of that cost on to consumers due to the cap. Since October 1 this has been £1,277 a year for normal energy use.
Pure Planet said: "The government and Ofgem, our regulator, expects Pure Planet to sell energy at a price much less than it currently costs to buy. This is unsustainable, and therefore, sadly we have had to make the difficult decision to cease trading."
A joint statement from the Pure Planet founders said: "If you’re a member, we thank you so much for putting your trust in us to supply renewable electricity and carbon-offset gas to your home.
"And we’re truly sorry to have let you down by not being able to keep Pure Planet going for you. We realise some may feel we could have said something about this sooner but, please believe us, our hands were completely tied by the law."
What to do if you are a Pure Planet customer
If your energy firm collapses, the advice from Ofgem is to sit tight and wait until your new supplier contacts you.
You should wait until you know which firm you've been moved to before you decide to look into switching elsewhere.
In the meantime, take a meter reading for when your new supplier contacts you so it can correctly bill you.
It is important to check prices as soon as you know which deal you've been moved to, as you may not necessarily be transferred over to the cheapest supplier.
You won't be charged exit fees for switching away from your new energy provider.
A number of energy firms have stopped taking on new customers as the supplier crisis engulfing the industry continues.
PfP Energy and MoneyPlus Energy both collapsed on September 7, followed by Utility Point and People’s Energy on September 14.
Green and Avro Energy were the next to go under, both ceasing to trade on September 22.
