A controversial voter roll revision exercise, SIR, in West Bengal may have played a decisive role in about half of the Assembly seats won by the Bharatiya Janata Party (BJP), according to analyses of data of election results and SIR.
The BJP won 207 of the state’s 294 assembly seats, ending Chief Minister Mamata Banerjee’s 15-year rule and securing its first government in West Bengal. But analysis of the data suggest that the scale and geographic concentration of voter deletions during the Election Commission’s “special intensive revision” (SIR) exercise closely overlapped with many of the BJP’s narrow victories.
The SIR process removed roughly 91 lakh names — about 12% of the state electorate — from voter rolls before polling. The deletions included “absent, shifted, deleted and displaced” (ASDD) voters and another 27 lakh names classified as “under adjudication” (UA), whose eligibility was later rejected.
Both analyses found that in half of the constituencies won by the BJP, the number of deleted voters exceeded the Hindutva party’s margin of victory.
A broader constituency-level analysis found that deletions outnumbered winning margins in 150 seats overall — more than half of West Bengal’s 294-member assembly.
Of those 150 constituencies, the BJP won 100 seats, while the TMC secured 48 and Congress won two.
The overlap was particularly striking in districts surrounding Kolkata, traditionally considered TMC strongholds. In North 24 Parganas, the TMC had won 23 of 26 highly affected seats in 2021. In the latest election, the BJP captured 21 of them. In South 24 Parganas, the TMC previously swept all 19 affected seats but lost 10 to the BJP this time.
Several high-profile defeats also occurred in constituencies where deletions vastly outnumbered victory margins.
In Tollyganj, state minister Aroop Biswas lost by 6,013 votes while nearly 38,000 voters were deleted. Banerjee herself lost Bhabanipur — held by the TMC since 2011 — to BJP leader Suvendu Adhikari by 15,105 votes after more than 51,000 names were removed from the rolls.
In Rajarhat New Town, the BJP won by only 316 votes while more than 63,000 names were deleted. In Satgachhia, a BJP margin of 401 votes coincided with over 26,000 deletions.
While the data suggests that the SIR was a significant factor shaping the electoral outcome, the analysis does not establish that the deletions directly altered results, since there is no evidence showing how the removed voters would have cast their ballots.
However, given that many of the affected constituencies have sizeable Muslim populations — a demographic that has traditionally voted for the Trinamool Congress (TMC) and other non-BJP parties — the deletions may have disproportionately disadvantaged the TMC.
For instance, in 49 seats where “under adjudication” (UA) deletions exceeded victory margins, the BJP won 26 despite the TMC having dominated nearly all of them in 2021.
In Jangipur, where Muslims account for more than half the population, UA deletions exceeded 36,000 while the BJP won by about 10,500 votes. In Samserganj, UA deletions crossed 74,000 against a TMC winning margin of 7,587.
The BJP had supported the SIR process throughout, arguing it was necessary to clean electoral rolls and remove ineligible voters. Opposition parties, including the TMC, had alleged the exercise disproportionately targeted minorities and migrant populations.
The Election Commission has maintained that the revision followed established procedures and legal scrutiny.
Even under simulations removing the effect of deletions, however, the BJP retained a clear majority, suggesting anti-incumbency against the TMC remained the dominant electoral force. Still, the analyses indicate that the voter roll revision may have materially shaped the margins in a substantial number of Bengal’s closest contests.