Martin Lewis issued energy advice after Russia's invasion of Ukraine sparked a "horrendous" price hike.
Energy bills are already set to soar by 54% in April due to the surging cost of wholesale gas.
The finance guru has maintained throughout the crisis that people should remain on their current tariff as there are no cost-effective fixed deals on the market.
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However, the crisis in Ukraine has prompted the price of UK natural gas to sky-rocket by 40% today.
A viewer contacted tonight's edition of Money Show Live to ask the consumer champion whether a fixed rate deal is now advisable.
Martin responded: "Energy prices have spiked horrendously today. If they stayed at that level, then in October we'd see another 50% rise in the price cap bringing the typical bill to £3,000 a year.
"We don't know whether that spike will continue. I've said before that if you could find a fix within 60% of the current price, it's probably worth it.
"Back of the envelope, it's probably now 80% if you want peace of mind to give you surety."
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