The Election Commission on Thursday asked 22 states and Union Territories to complete preparatory work related to the Special Intensive Revision (SIR) at the earliest as the exercise is "expected to start from April".

Once the exercise is completed, all states and UTs will be covered.

In a letter to the chief electoral officers of Andhra Pradesh, Arunachal Pradesh, Chandigarh, Dadra and Nagar Haveli & Daman and Diu, Haryana, Himachal Pradesh, Jammu and Kashmir, Jharkhand, Karnataka, Ladakh, Maharashtra, Manipur, Meghalaya, Mizoram, Nagaland, Delhi, Odisha, Punjab, Sikkim, Tripura, Telangana and Uttarakhand, the poll authority said pan-India SIR of voters' list was ordered in June last year.

In Bihar, the SIR exercise was completed and is ongoing in nine states and three UTs.

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