French energy giant EDF is charging UK households almost two-and-half times more than those across the Channel.
EDF customers in Britain have their annual bills capped at £1,971 under a system overseen by the regulator Ofgem. But French customers on regulated tariffs face bills of around €950 (£803).
And while Ofgem is expected to announce an eye-watering 80% surge in its price cap at the end of this month, French President Emmanuel Macron has told state-owned EDF it can only increase bills by 4%.
The French government has forced EDF to sell electricity generated by its nuclear reactors to rival suppliers at well below market prices so it can keep low prices for consumers.
And Mr Macron has unveiled plans to nationalise EDF so he can have more control over the its plans for domestic energy prices.
The drastic measures contrast with the UK, where the lame duck Tory government has been accused of doing nothing new to help households face astronomical energy bills.
Joe Malinowski, founder of price comparison service TheEnergyShop.com said: “When you see a difference like this you’d think there was something wrong with prices in the UK.”
It comes as economists predict figures out next week will show inflation soared to nearly 10%, figures last month. Research consultancy Pantheon Macroeconomics forecasts the Office for National Statistics will announce the consumer prices index (CPI) measure of inflation leap from 9.4% in June to 9.9% in July - a new more than 40-year high.
The Bank of England predicts inflation will top 13% after the October wave of energy price hikes.
In better news, average petrol prices are expected to drop below 175p a litre this weekend. with diesel down to 185.90p, say the AA.
Meanwhile, the Government is considering whether to give further help to businesses struggling under the weight of their energy bills even as it refuses to commit to helping households more.
Business Secretary Kwasi Kwarteng said that it is “essential” to help heavy industry to cut production costs.
He is proposing that the Government increases the exemption from some environmental and policy costs that certain companies were given in March.
The new proposal would increase the exemption from 85% to cover 100% of the costs.
