Narendra Modi-government’s surprise move to increase excise duty and cess on petrol and diesel to take advantage of the falling global crude oil prices may not help the exchequer in raising tax revenues by much. “We do not expect the Central government to accrue a sizable amount as excise duty revenue, given the current economic slowdown,” Care Ratings said in a report. The slowdown has led to a sharp fall in demand for petrol and diesel as the tenacity of the lockdown imposed and when it will be lifted is still unknown, the report added.