Martin Lewis has warned how households face being forced to choose between heating and eating this winter unless they receive immediate support.
The MoneySavingExpert founder told ITV News that surging gas prices will have a “frankly catastrophic” impact on millions of Britons later this year.
He called on the Government to urgently intervene with tailored support for struggling families.
It is estimated that the energy price cap will jump to a crippling £3,500 in October - with further rises expected in January next year.
Mr Lewis warned that this is “simply unaffordable for millions of homes” and is likely to tip upwards of 10 million people into fuel poverty.
"The impact of it is frankly catastrophic and intervention is needed, and needed now," he said.
Urging the Government to act now, he added: “What we need is a willingness to take action and to grasp this, to make sure there are millions of people in this country who don't face the choice between starvation and freezing this winter.
“It's looking like that is a realistic choice if nothing is done for many."
What is behind the price hike?
The UK was already facing higher energy bills before the war in Ukraine, due to increased demand following the Covid pandemic.
Russia, which is one of the biggest global energy suppliers, has been steadily choking off supplies in recent months, causing disruption and higher prices in the process.
The country supplies 40% of the EU’s natural gas via a network of pipelines running from Russia to Europe.
Countries that are most reliant on Russian gas are particularly vulnerable to disruptions, such as Germany which imports around 55% of its gas from Russia compared to 4% in the UK.
However, the nature of energy markets being global means that prices are still affected.
The UK gets 50% of its gas from UK gas fields and the government says the UK energy price crisis is due to high global prices for oil and gas, not because of supply issues.
The most recent price spike is owing to Russia restricting gas flow through the Nord Stream pipeline which runs to Germany.
In June, Russia cut gas flows through this pipeline to just 40% of its normal capacity.
They claimed that this was a result of an issue with the delayed return of a gas turbine owing to sanctions imposed by both the EU and US against Russia.
Sending high prices soaring, the Russian company that operates the pipeline, Gazprom, shut it down entirely for ten day in July for annual maintenance.
While Gazprom resumed gas flows to 40% capacity, it announced this week that it was dropping gas flows again to around 20% owing to a ‘technical condition’ with a turbine engine.