The Chennai cluster’s share in the overall elector base fell from 18.37% to 16.1%, while the Tiruppur cluster remained fairly steady at around 14%.
More than half of the total electors removed in the integrated draft electoral roll following the Special Intensive Revision (SIR) exercise in Tamil Nadu were from just two clusters comprising eight districts – four in the north of the State and four in the western region (with one in the southwestern region).
For this analysis, Chennai and its neighbouring districts such as Tiruvallur, Kancheepuram and Chengalpattu were grouped as one cluster, while Tiruppur and its neighbouring districts such as Coimbatore, Erode and Dindigul were grouped as another.
One-fourth of the total electors in the Chennai cluster were removed, reducing the electorate from 1.17 crore spread across 37 Assembly segments to 87.54 lakh. Similarly, the 33 Assembly segments falling under the Tiruppur cluster recorded the removal of 19.42% of electors. A total of 18.64 lakh electors out of 96.01 lakh were removed. Together 50.17% of total electors were removed from these eight districts.

Even though these two clusters saw the highest removals, the impact on their share of Tamil Nadu’s total elector base was relatively limited. The two clusters continue to dominate the elector base. Before the SIR exercise, their combined share stood at 33.34% of the total electorate. As per the draft roll, this has declined to 30.33%.
The Chennai cluster’s share in the overall elector base fell from 18.37% to 16.1%, while the Tiruppur cluster remained fairly steady at around 14%. Experts pointed out that one reason for the high level of deletions in these districts could be the density of the electors base.
Venkatesh Athreya, a development economist and former professor at Bharathidasan University, said one possible reason for the large-scale deletions in the two clusters was the high concentration of migrant workers linked to greater industrial activity. Many of these workers may have been enrolled in the districts earlier but later returned to the villages or towns from where they had come to work in Tamil Nadu, particularly during the COVID-19 period.
Published – December 21, 2025 12:45 am IST