The government proposes to roll out the GST, a new indirect tax regime which will subsume various levies including sales tax, excise, service tax, from 1st April 2016.
Finance Minister Arun Jaitley on Thursday held discussions with state finance ministers on the roadmap for rolling out the GST, where most states, barring Tamil Nadu, gave their assent on its provisions.
Once the Constitution Amendment bill is approved by Parliament by two-third majority, it will have to be ratified by half of the states.
The Bill on GST was introduced in the Lok Sabha in December last.
Jaitley had earlier said that implementation of the landmark GST regime would increase the GDP by 1-2 percent.
The Centre has been working towards addressing concerns of all states for rolling out the GST on the scheduled date.