Leading car manufacturers have urged the government to give clarity on its proposed row back on banning petrol and diesel cars, saying they’ve invested hundreds of millions to meet targets. Mike Hawes, chief executive of the Society of Motor Manufacturers and Traders (SMMT), said the policy change will cause “concern” among car makers. It has been widely reported that the ban on the sale of new petrol and diesel cars and vans will be pushed back from 2030 to 2035. Mr Hawes told BBC Radio 4’s Today programme that high demand…