"The GST would grab the power of the states and the central government would be more powerful in the new tax regime," Sarkar told reporters here on Monday night.
Sarkar, a member of the Communist Party of India-Marxist (CPI-M) politburo, said there are opinions against as well as in favour of the GST.
"Whether a state like Tripura would be a loser or gainer, officials are calculating. I would not pass any comment on this at this moment," he said.
"It is a matter of concern that one after another the central government has been taking powers of the states. The federal structure of our governance must be upheld for strengthening the democracy," he said.
The Lok Sabha on Monday passed the amendments to the GST Bill adopted by the Rajya Sabha during its passage last week.