British Gas is to increase prices for domestic customers, with a dual-fuel bill going up by 9.2% from 23 November.
The increase, which will affect nearly eight million households in the UK, includes an 8.4% rise in gas prices and a 10.4% increase in electricity prices.
The company said it "understands the frustration" of prices rising faster than incomes. The average annual household bill will go up by £123.
PM David Cameron has urged consumers to switch suppliers for the best deal.
Not being troubled by such mundane matters as gas bills, Mr Cameron cannot be expected to understand that the energy providers are all in it together: when one of them puts up its charges, the others follow suit.