Mail on Sunday: A cabinet minister welcomed spiralling petrol prices last night as an incentive for drivers to make fewer car journeys. Environment Secretary Hilary Benn said the high cost of oil helps force people off the road and reduce greenhouse gas emissions. He also launched a robust defence of road tax rises for more than nine million cars – insisting it was right that they should also apply to second-hand vehicles. Mr Benn’s remarks triggered a backlash from motoring groups, …