Household gas and electricity bills are set to soar after the energy price cap went up by 10%.
Ofgem announced that the limit will increase by from £1,568 to £1,717 from October 1 in England, Scotland and Wales, adding around £12 a month to the average bill.
Jonathan Brearley, the watchdog’s chief executive, said: “I talk to many many families and I know that today’s news is not going to be welcome.”
He said the rise had been “driven principally by the change we’re seeing in international gas prices”.
And he added: “I think what we need to accept is this situation of volatile gas prices ... is likely to be around for a long time.”
The announcement comes just weeks after chancellor Rachel Reeves announced that winter fuel payments will be scrapped for all pensioners who are not on benefits.
Reacting to Ofgem’s announcement, energy and net zero secretary Ed Miliband blamed the last Tory government.
He said: “This will be deeply worrying news for many families. The rise in the price cap is a direct result of the failed energy policy we inherited, which has left our country at the mercy of international gas markets controlled by dictators.
“The only solution to get bills down and greater energy independence is the government’s mission for clean, homegrown power. That’s why we have hit the ground running, lifting the onshore wind ban, consenting unprecedented amounts of solar power and setting the largest ever budget for our renewables auction.
“We will also do everything in our power to protect billpayers, including by reforming the regulator to make it a strong consumer champion, working to make standing charges fairer, and a proper warm homes plan to save families money.”
Shadow energy secretary Claire Coutinho said: “Instead of prioritising cheap energy, the new Labour Government are pursuing Ed Miliband’s reckless net zero targets with no thoughts to the costs.
“And far from their promise of saving families £300 off their energy bills, one of their first acts in office is to remove the winter fuel payment from 10 million pensioners.
“Because they weren’t honest about their plans that means millions of pensioners will have made no plans to deal with higher energy bills this winter.”
Green Party co-leader Carla Denyer said “consumers are paying high prices for a crisis not of their making”.
She added: “We need a nationwide programme of government-backed, council-delivered home insulation starting immediately to help people keep their bills down for good.