Wholesale gas prices will be higher later in 2012, warned British Gas. The well-known energy supplier's owners said gas costs would be 15% more expensive next winter, adding: "The trend for retail energy costs therefore remains upwards." British Gas customers last August saw a 16 per cent rise in electricity prices and an 18% rise in gas prices. Price comparison website Uswitch representative Tom Lyon said: "Any further increases will see even more people seriously struggling to afford their bills."