LONDON - Prime Minister Boris Johnson will say on Thursday that the recent rise in energy prices is a warning that Britain cannot be left at the mercy of international markets or "foreign despots" to meet its energy needs.

Europe is facing massive increases in energy bills driven by rocketing gas prices as Russia's move to throttle European supplies amid the war in Ukraine drives wholesale gas prices to record highs.

British energy bills will jump 80 per cent to an average of 3,549 pounds (S$5,800) a year from October, plunging millions of households into fuel poverty.

In one of his final speeches before he steps down next week, Johnson will defend his handling of the current energy crisis, saying his government's decision to increase production of domestic gas, reverse decades of underinvestment in nuclear and increase investment in renewable energy will reduce the dependency on foreign fossil fuels.

"The big decisions this government has made on our energy future will bequeath a United Kingdom where energy is cheap, clean, reliable, and plentiful," Johnson will say. "A future where families and businesses are never again at the mercy of international markets or foreign despots."

Despite one of the worst cost-of-living crises in decades, Britain's response has been hampered by the race to replace Johnson that runs until Sept 5, focused on the votes of Conservative Party members keen on tax and spending cuts.

Johnson, who was forced to resign over a string of scandals, said last week the government would announce further support soon for consumers struggling with energy bills and this should be targeted at the most vulnerable rather than all households. REUTERS