"I am trying to stick to the time schedule, but I will not be surprised if there is slippage of a few months," Mukherjee said at the Hindustan Times Leadership Summit in New Delhi.
The finance minister's comments came on a day when states finance ministers deliberated on various aspects of GST structure at a meeting in New Delhi.
In fact, Mukherjee also said, "Right now, the empowered committee of state finance ministers is meeting in Delhi. It means that we are seriously trying for convergence of the views, I am going to have meeting on 10th of next month."
He said convergence has been arrived at on many issues and divergence is limited.
"But at the same time, it will take some legislative measures, including the constitutional amendment, and that has its own space," he said.
Asked about the finance minister's comments on the issue, empowered committee chairman Asim Dasgupta said, "Our collective target is April 1, 2010, and on this we will have discussions with the finance minister."
The empowered committee has already constituted a working group on suggesting Constitutional amendments and model GST Act.