A future road map could well be to work towards a single standard Goods and Services Tax (GST) rate instead of two standard rates of 12 and 18 per cent, Union Finance Minister Arun Jaitley said on Monday.

"It could be a rate at some mid-point between the two standard rates of 12 and 18 per cent. Obviously, this will take some reasonable time when the tax will rise significantly. The country should eventually have a GST which will have only slabs of zero, 5 per cent and standard rate with luxury and sin goods as an exception," he wrote in a Facebook blog.