trade, britain s only surviving cloth hall opens after a multi million pound renovation. good morning. it s tuesday 1st august. i m julian worricker. welcome to bbc newsroom live. british gas has said it will increase the price of electricity for the first time in nearly four years. its owner centrica says electricity prices will increase by 12.5% from 15th september. 3.1 million customers will be affected. but the company s gas prices will be held at their current level. the average annual dual fuel bill for households on a standard tariff will rise by £76, up by 7.3%. ian conn is the chief executive of british gas‘s parent company, centrica. he explained why the price rise was necessary despite a decrease in the wholesale cost of energy. first of all, the last time we moved our electricity prices was in january 2014 and since then they have been held flat. from that time, and you are correct, wholesale prices have fallen, we estimate about £36 on an average bill, that i