Goods and service tax (GST) collections could see a dip of 10-20% in May as Maharashtra - the largest state contributor to GST - and Madhya Pradesh enforce lockdown-like curfew rules even as other states have imposed night curfews to control the rising number of Covid cases."With closed shops, businesses, supply-chain bottlenecks, restricted movements etc, tax collections are set to fall nationally by 10-20% in May, and for states like Maharashtra which is the highest contributor, the collections are likely to reduce by half,” said Harpreet Singh, indirect tax partner at KPMG India.Maharashtra clocked Rs 17,038 crore in GST collections in March, which is 18.5% of state GST of Rs 91,869 crore, as per data released earlier this month."The immediate impact will be felt by auto, cement and other manufacturing led sectors that have sent inventory to dealers who will now be stuck with no secondary sales. This will put further pressure on working capital," said MS Mani, partner at Deloitte India.