British Gas has announced a 7% rise in gas and electricity bills this winter, the increase coming into effect on December 10. The company said this was the result of rising wholesale prices. The energy giant said prices for those on a typical dual-fuel deal would go up by £1.50 a week, but its 300,000 most vulnerable customers would initially not be charged more. The rise affects eight million customers, and British Gas is the second major UK energy supplier to hike prices for winter.