BIG SIX bosses have “no excuses” not to slash gas bills, campaigners and MPs said yesterday, as the energy barons’ costs dropped to a record low.

Energy markets yesterday showed wholesale gas trading at 37.55p per therm, marking a continued drop from around 70p in December and the lowest rate in nearly four years.

Yet the average household gas bill has rocketed from £676 in 2013 to an estimated £716 this year.