New Delhi | Voter base in nine states and Union territories has shrunk by more than 1.70 crore following the publication of final electoral rolls as part of the ongoing Special Intensive Revision (SIR), according to official data released on Saturday.

Data shared by the chief electoral officers of Gujarat, Puducherry, Lakshadweep, Rajasthan, Chhattisgarh, Andaman and Nicobar Islands, Goa and Kerala showed their combined voter base stood at over 21.45 crore before the SIR exercise began on October 27 last year.

It shrunk to 19.75 crore after publication of their final electoral rolls this week -- a net change of over 1.70 crore electors.

While the exercise, which kept the Election Commission in the spotlight, has been completed in Bihar, it is currently underway in 12 states and Union territories covering nearly 60 crore electors.

The remaining 40 crore electors will be covered in 17 states and five Union territories.

In Assam, a "special revision", instead of SIR, was completed on February 10.

Due to a variety of reasons, the SIR in the nine states and three Union territories have seen frequent tweaking in schedules. As in Bihar, political parties have approached the Supreme Court challenging the exercise in Tamil Nadu and West Bengal.