GAIL chairman Sandeep Kumar Gupta said the government should mandate the use of natural gas in refineries and steel making, and make emissions a factor in the merit order for electricity despatch to help gas-based power compete with coal-based supply. He also said natural gas should come under the goods and services tax (GST) regime, production-linked incentive (PLI) should be extended to LNG-powered vehicles and GST on CNG-powered vehicles should be slashed to 5% from 28%, on a par with electric vehicles (EVs).