British Gas is reportedly planning to raise its prices by 100 pounds or eight per cent, bringing energy bills up to record levels. Britain's biggest energy company, owned by London-listed Centrica, is expected to make the announcement next month, sources told The Telegraph.The report comes after weeks of speculation on predictions from experts on price rises. Peter Atherton, an analyst at Liberum, said an 8% jump seemed likely given the rising cost of environmental levies and transmission charges.The firm, which supplies 12m homes in the UK, responded by saying it "never comments on future pricing movements".British Gas has been defending its high bills over the past year, blaming the government's green agenda for the inflationary pressures.Parent company Centrica's shares were up 1.33% to 402.90p at 16:02 on Friday.RD