"In principle our government supports GST. In our election manifesto also, we had said we want GST. But the question is whether the state's loss of revenue will be compensated. 29 states, not only Bengal, have raised this as a problem," Mitra told reporters here.
He said a single tax of GST was needed, but the states would loose revenue.
"All state finance ministers have said GST should be done in a way that the states don't loose anything. They have to give a constitutional guarantee," Mitra said.
"You don't have to pay VAT on paper now. Everything is done on computer. In no other state, demat certificates are given by the government," Mitra added.