The BJP’s victory in West Bengal has drawn strong reactions across the political spectrum, ranging from celebratory praise to deep shock and disbelief. While the winners, led by Prime Minister Narendra Modi, have claimed it to be an anti-incumbency mandate for change, defeated former chief minister Mamata Banerjee has complained of electoral manipulation and dishonesty. It seems the truth lies somewhere in the middle.
Double effect: SIR and polarization
What stood out in the two-phase West Bengal assembly elections was an unprecedented voting rate of over 93%, compared to 82% in the 2021 assembly elections and 79% in the 2024 Lok Sabha elections. This 93% figure, apparently the highest recorded in a general election in any major Indian state, was inflated by the low base effect, as the number of voters was reduced by about 80 lakh following the special intensive revision (SIR) of electoral rolls in West Bengal.
The SIR exercise began on November 4, 2025 in West Bengal along with 11 other states and union territories. While initially it was to be completed by the end of January 2026, a new criterion of “logical discrepancy” was introduced by the Election Commission of India (EC), in West Bengal only, to identify and remove excess voters from the electoral rolls. This began an extended process of hearings, judicial intervention, adjudication and ultimately an appellate tribunal that continues to this day, and is likely to continue for many years. Reportedly, more than 34 lakh appeals are pending in the appellate tribunals.
collectively Deletion of electorates on an unprecedented scale as well as large numbers of opaque additions had a major impact on the demographic composition of the rolls. This appears to have decisively influenced the election results, in addition to significant anti-incumbency and communal polarization.
While the total number of voters in West Bengal declined from 7.34 crore in 2021 to 6.81 crore in 2026, the total valid votes increased from about 6.03 crore to 6.37 crore. Total votes cast in favor of All India Trinamool Congress (AITC) dropped from 2.89 crore in 2021 to 2.60 crore in 2026 – a drop of 29.5 lakh in total votes. In contrast, BJP’s total votes increased by 63 lakh, from 2.29 crore in 2021 to 2.92 crore in 2026. The total votes and voteshares of CPI(M) and Congress remained broadly similar (Table 1).
The relative magnitude of each component of the dual effect of SIR and anti-incumbency-co-polarization can only be understood in the context of the religious-demographic divide of SIR extinction. Since religious-demographic data on voters is not maintained or published by the Election Commission, this analysis relies on digital scrutiny of voter lists and deletion lists for the high-profile constituency of Bhawanipur, where BJP’s Suvendu Adhikari defeated Ms Banerjee. Due to the absence of other reliable data from recent years, the 2011 population census has been used to calculate the estimated population of Muslims at the district and state levels.
Deletion under SIR in West Bengal took place in three phases, viz., enumeration; Claims and objections; And decision. Of the total 58.2 lakh ASDD (absent, transferred, dead, duplicate) deletions in the first phase, 32 lakh were classified as absent or transferred. Digital scrutiny of ASDD lists revealed that about 7.34 lakh (23%) of the absentee or transferred voters were Muslims. Of the 27.16 lakh voters removed after the judgment, which were mainly “logical discrepancy” (LD) cases, about 17.65 lakh (65%) were Muslims (Table 2).
Thus, excluding deletions under deceased and duplicate categories, out of the total 64.7 lakh state-wide SIR deletions, more than 25 lakh were Muslims, i.e., 38.6%, which is higher than their proportion of 27% in the population as per 2011 Census.
Statewide SIR Impact Analysis
Assembly constituency-wise analysis of the impact of a total of 67.26 lakh SIR changes – defined as the sum of deletions and additions across SIRs under absent, transferred and LD cases – was conducted by a team of experts. Chart 1 shows the district-wise distribution of these SIR changes, along with the district-wise shares of the estimated size of Muslim voters, calculated by applying the district-wise percentage of Muslim population reported in the 2011 census. This brings the estimated number of Muslim voters to 1.77 crore (26%) out of the total 6.81 crore voters.
Chart 1 clearly shows that the number of SIR changes (deletions under the three categories and additions, as mentioned earlier) was very high in 12 districts with a high number of Muslims, namely North 24 Parganas, Kolkata, Murshidabad, South 24 Parganas, Howrah, Malda, Hooghly, Nadia, Purba Bardhaman, West Bardhaman, North Dinajpur and Birbhum. These 12, which accounted for over 84% of Muslim voters, also accounted for over 80% of the SIR changes.
Since six of these districts do not share any international border with Bangladesh, the high changes under SIR cannot be easily explained in terms of suspected cross-border illegal migrants. Rather, it seems that the entire minority population of Muslim concentrated districts was placed under suspicion during the SIR process. This is corroborated by the findings of independent studies reported in the mainstream media, which state that at least 37% of the total people deported under the SIR were Muslims.
AC-wise analysis of the results shows that out of the 207 seats won by the BJP in 2026, the magnitude of SIR change was more than the BJP’s victory margin on 82 seats. Of these, 70 were located in 12 Muslim-concentrated districts. In 2021, BJP won only 9 of these 82 assembly constituencies. In 2026, SIR changes have decisively affected the election results in these 82 ACs. In other words, it is not impossible that the BJP would have failed to win a majority in the West Bengal Assembly elections without the influence of SIR.
Effect of SIR in Bhabanipur
This pattern of disproportionate deletion of Muslim voters possibly influencing the results is evident in Bhawanipur constituency, where digital scrutiny of polling station-wise ASDD lists and voter lists revealed that out of the total 36,664 deletions under absentee, transferred and LD categories, 9,481 (26%) were Muslims (Table 2). This proportion of 26% is significantly higher than the 20% share of Muslims in the population of Kolkata district in 2011. These deletions of Muslim voters were highly concentrated in divisions 1 to 112 (polling stations) falling under wards 63, 77 and 74 of the Kolkata Municipal Corporation, where the Muslim population is high.
Furthermore, while Muslims contributed 26% of the deletions, they accounted for only 19% (1,025) of the 5,408 additions to Bhabanipur’s voter list.
AITC’s victory margin over BJP in Bhawanipur assembly constituency had already shrunk from 58,835 in the 2021 bypoll, which Ms Banerjee won with 72% vote share, to 8,297 in the 2024 Lok Sabha election.
The net deletion (total deletion excluding additions) of Muslim voters in Bhawanipur AC during SIR was 8,456.
In the 2026 election, 5,524 more valid votes were recorded in Bhabanipur than in 2024, which incidentally is of the same magnitude as the total of 5408 during the SIR.
Between 2024 and 2026, the votes polled by the AITC declined by 3,649, while the votes polled by the BJP increased by 19,753 (Table 3).
Additionally, the votes polled by CPI(M) declined by 10,540 and the votes polled by all others declined by 1,448 between the two elections. There is a possibility that these votes may go in favor of BJP in 2026. However, such a swing in favor of the BJP is unlikely to have happened in the constituency, if not for the SIR which has reconfigured the demography.
This raises new questions on the intent and validity of the SIR, which must be addressed by the Supreme Court to prevent recurrence in other states. The dysfunctional and ineffective appellate mechanism in West Bengal needs to be strengthened to ensure justice for all those wrongfully removed through opaque, discriminatory and arbitrary processes.
The Election Commission must be held accountable for conducting the SIR in a manner that not only collectively The disenfranchisement of genuine voters on the eve of general elections not only jeopardizes the future of free and fair elections in the country, which is the cornerstone of parliamentary democracy. The Election Commission should publish a comprehensive statistical report of all SIR-related data on deletions, additions and amendments in the electoral rolls in West Bengal, which have not been officially reported so far, to facilitate further independent analysis and judicial scrutiny.
Prosenjit Bose is an economist. He heads the SIR committee of the West Bengal Pradesh Congress Committee.
