"VAT will not be deferred, irrespective of whether Uttar Pradesh joins or not," VAT panel chairman Asim Dasgupta said after a marathon meeting with state finance ministers in New Delhi.
He, however, said the committee would try to convince Uttar Pradesh about the benefits of VAT.
"We met UP Chief Minister Mulayam Singh Yadav and he had assured us that they would be sending a delegation," Dasgupta, who is also the West Bengal Finance Minister, said.
The crisis over VAT: Complete coverage
Apart from Uttar Pradesh, Jharkhand is the other state which is not ready for VAT due to the "political uncertainties", he said.
Some other states like Rajasthan and Madhya Pradesh have demanded a "clear roadmap" on the phasing out of the 4 per cent Central Sales Tax.
Dasgupta said VAT panel would meet the Finance Minister P Chidambaram for preparing the phase-out of CST.
According to the initial agreement between Centre and the states, CST will stay in the first year of VAT introduction.
Some of the states like Madhya Pradesh want to switch over to the new tax regime only if all states do so.