How deletion of over 9 million voters out of Bengal list is a blow to TMC

With over 9 million names removed after SIR, West Bengal's voter list has triggered a political flashpoint, raising questions over the impact on TMC's core support base

With barely two weeks left for voting in West Bengal, a technical exercise on electoral rolls has turned into a high-stakes political fight. A Special Intensive Revision (SIR) of voter lists led to the deletion of more than 9 million names, roughly 12 per cent of the West Bengal electorate comprising 76 million voters, thus compressing the voter base ahead of polling on April 23 and April 29. The scale, timing and geography of the deletions have placed the Trinamool Congress (TMC) on the defensive and given the opposition Bharatiya Janata Party (BJP) a new campaign plank.

 

What exactly has happened to Bengal’s voter list?

 

The revision has sharply reduced the size of the electorate compared with the previous rolls finalised in late 2025. Data released by the Election Commission of India shows that over 9 million entries have been removed following verification and adjudication processes.

 

 

The impact is uneven across the state. Border districts such as Murshidabad, Malda and North 24 Parganas have recorded some of the steepest declines, regions where the overwhelming number of sitting MLAs belong to the TMC. These are also regions with dense populations, high migration and historically competitive contests.

 

In Kolkata, the effect is visible at the constituency level. In Bhowanipore, Mamata Banerjee’s seat, tens of thousands of voters have been struck off the rolls. And this is not a marginal clean-up as a double-digit contraction in the voter base will alter turnout baselines and can decisively shift margins among the tightly fought seats.

 

What is SIR and why is it conducted?

 

SIR is a periodic exercise by the Election Commission to update electoral rolls, involving house-to-house verification and stricter document checks, unlike regular revisions.

 

The aim of conducting such a revision is to eliminate any duplicate entries, delete names of dead or moved individuals, and only retain those who have the right to vote. Those eligible must provide supporting documents within a specified period; otherwise, their names can be removed.

 

The Election Commission has consistently maintained that such exercises are essential to maintain the integrity of elections. However, the process is often contentious because of the volume of exclusions it can generate within a compressed timeline.

 

Why does this hurt TMC more than others?

 

The political significance of the SIR carried out in Bengal lies less in the act of revision and more in where and how it has played out.

 

Several of the districts with the highest deletions overlap with areas where the TMC has built strong electoral coalitions over the past decade. Thus, any reduction in the voter base in these pockets introduces uncertainty into what were previously considered stable segments.

 

Political commentators have also pointed out that there is also a structural issue because elections in West Bengal are often decided by narrow margins at the constituency level. A reduction of even a few thousand voters in specific booths can change outcomes, particularly in urban and semi-urban seats.

 

Meanwhile, the BJP has framed the deletions as a necessary correction to remove “ineligible” entries, including alleged “infiltrators”. This allows it to turn a bureaucratic exercise into a political argument about citizenship and legitimacy.

 

For the TMC, the challenge has become twofold: it must address the immediate electoral impact while contesting the broader framing of the exercise.

 

How has Mamata Banerjee responded?

 

The revision of the electoral roll is one of the main agendas Chief Minister Mamata Banerjee has taken up during her election campaign. At public gatherings and through various media statements, she has claimed that the exercise is partial, as names of members of certain communities were being deleted from the electoral roll. She has warned that the exercise might disempower genuine voters.

 

She has highlighted similarities between previous similar exercises, warning that such document-requiring exercises could exclude people from voting.

 

Organisationally, the TMC has urged concerned voters to apply for restoration to the electoral roll within the available legal means.

 

What happened in Bihar when SIR was implemented?

 

Before Bengal, Bihar implemented SIR prior to the 2025 state elections. The exercise saw the exclusion of millions of people from the voting list, resulting in a huge controversy where opposition parties claimed that those excluded largely belonged to minority communities.

 

The issue also reached the judiciary, with multiple petitions being filed in the Supreme Court.

 

The Election Commission, however, defended the revision as a necessary clean-up to improve the accuracy of voter lists.

 

What does this mean ahead of West Bengal polling?

 

With the electoral rolls in Bengal now finalised after two phases, this makes the impact of the voter deletions more immediate than theoretical.

 

For the TMC, the key objective now appears to be containing losses in the constituencies that have been affected and boosting voting by the registered electorate. For the BJP, the idea is to keep alive the storyline of how the revisions have increased confidence in the process.

 

In elections with close margins, the key issue is not so much whether the list has been revised as how those changes will affect the vote count on May 4.