Following the publication of early trends for the 2026 West Bengal Assembly Elections by the Election Commission of India and ADR, the impact of the much debated Special Intensive Revision (SIR) on the electoral landscape of West Bengal has become much more apparent nationwide.

Data provided by the Election Commission of India (ECI) and independent SIR impact analysis suggest a seismic shift in the state’s traditional vote banks, particularly across the border districts and the critical Murshidabad belt.

Early trends: BJP surges, TMC trails

According to current trends, the Bharatiya Janata Party (BJP) has taken a commanding lead in 157 seats, crossing the majority mark of 148. The Trinamool Congress (TMC), meanwhile, is trailing significantly, leading in only 53 seats. This represents a sharp departure from the 2021 results, a change analysts attribute largely to the implementation of the SIR process.

While early ECI trends at 10:49 AM showed the BJP leading in 92 seats and AITC (TMC) leading in 52 (out of 147 trending seats), broader impact assessments suggest a final shift of 157 seats for the BJP compared to just 53 for the TMC. The diverging fortunes in Bengal highlight the unique impact of administrative interventions on electoral outcomes.

How did SIR impact BJP and TMC vote bank

A pivotal factor in these numbers is the impact of voter exclusions. The SIR process has excluded approximately 27 lakh voters from the electoral rolls, citing ‘logical discrepancies’ and other verification factors. (Where voters may have moved or died.)

While broader estimates from SIR impact reports suggest a total of 91 lakh voters were removed across the state’s 294 constituencies, the 27-lakh figure represents a core demographic shift that has directly affected the competitive margins of the ruling TMC.

Murshidabad: Worst hit district from SIR

Murshidabad, a district with a 67% Muslim population and 22 assembly seats, has emerged as the highest-impact zone under the SIR. Approximately 4.5 lakh voters were deleted in this district alone, the heaviest per-capita deletion in the state.

As per independent analysts, the high number of deletion of voters in Murshidabad has affected the number of votes coming from the sizable Muslim community in the region that previously served as a reliable votebank for Mamata Banerjee led TMC. There are an estimated 41-54 Muslim-decisive seats at stake where this consolidation remains the primary counter-force to the SIR-driven shift.

In a development described as the most dramatic demographic shift post-SIR, the Jangipur constituency has reportedly flipped from a Muslim-majority to a Hindu-majority electorate.

Mahua and Matua Belts: The Border Factor

The impact is equally pronounced in the Mahua (Matua) and border belts, where the SIR, CAA, and immigration narratives converge. Classified as a district that was extremely significantly impacted by the much debated SIR exercise, this district saw roughly 3.8 lakh deletions.

In North 24 Parganas and Nadia, the Matua community (frequently associated with Mahua-belt politics in the state’s tribal and forest fringes) remains the decisive factor. The SIR Impact Analysis categorizes the Matua-heavy regions as an high impact zone, particularly due to the intersection of SIR and CAA (Citizenship Amendment Act) narratives.

As per independent analysts, the post-deletion data indicates a visible rise in the Hindu vote share in border constituencies such as Chopra, Islampur, Goalpokhar, and Farakka. Analysts from News18 a suggest that while deletions have reduced the absolute voter base, they have simultaneously spiked turnout among the remaining electorate in these belts, particularly among communities seeking to affirm their citizenship status.

West Bengal 2026 | Special Intensive Revision
SIR Impact on WB Assembly Seats
~91 lakh voters removed from electoral rolls — district-wise breakdown across all 294 constituencies
Total Deleted ~91L
Highest Impact Murshidabad
V High Seats 60-70
Muslim-decisive 41-54
!
Highest Impact District Murshidabad — ~4.5 Lakh Deleted 22 seats | 67% Muslim district | Heaviest per-capita deletion in state | Jangipur reportedly flipped from Muslim to Hindu-majority post-SIR
SIR District Summary — Approximate Deletions
Murshidabad 22 seats | 67% Muslim
~4.5L
N 24 Parganas 33 seats | Basirhat-Baduria worst
~3.5L
Nadia 17 seats | MATUA heartland
~3.0L
Malda 12 seats | Mothabari/Ratua worst
~2.5L
S 24 Parganas 31 seats | Metiaburuz / Bhangar
~2.5L
Uttar Dinajpur 9 seats | 50% Muslim | Border
~2.0L
Cooch Behar 9 seats | Rajbongshi SC | Border
~1.5L
Key Electoral Dynamics
1
The SIR Paradox Designed to remove bogus voters, SIR disproportionately deleted both Muslim AND Matua (Hindu refugee) voters — cutting across communal lines and hitting two opposing electoral blocs simultaneously.
2
Matua Backlash BJP’s own vote bank — the Matua community — was hit by SIR in Nadia and N24P. Ranaghat booths saw 78% deletions. May cost BJP 10+ seats they were counting on.
3
Muslim Consolidation SIR may drive 2021-style Muslim polarisation toward TMC as the ‘protector’ narrative — with ~41-54 Muslim-decisive seats at stake, this is the single largest bloc in the election.
4
Jangipur Flip — Most Dramatic Single Change Jangipur (Murshidabad) reportedly flipped from Muslim-majority to Hindu-majority post-SIR. The most dramatic demographic shift by a single constituency in the state.
5
Border Factor 50+ constituencies sit on the Indo-Bangladesh border. Immigration, SIR and CAA converge here — with Hindu share visibly rising in Chopra, Islampur, Goalpokhar and Farakka post-deletion.
6
SC and ST Belts 68 SC seats spread across state (Namasudra/Matua in east, Rajbongshi in north). 16 ST seats concentrated in Jangalmahal (west) and Dooars (north). SIR hits SC-reserved constituencies hard in Cooch Behar.
V HIGH IMPACT — Districts with Constituency Breakdown
1
Murshidabad22 seats | 67% Muslim
~4.5L
V HIGH
2
N 24 Parganas33 seats | Basirhat-Baduria belt
~3.5L
V HIGH
3
Nadia17 seats | MATUA heartland
~3.0L
V HIGH
4
Malda12 seats | Mothabari/Ratua worst
~2.5L
V HIGH
5
S 24 Parganas31 seats | Metiaburuz, Bhangar
~2.5L
V HIGH
6
Uttar Dinajpur9 seats | 50% Muslim | Border
~2.0L
V HIGH
7
Birbhum11 seats | Nalhati/Murarai worst
~1.8L
HIGH
HIGH IMPACT — Districts with Significant Deletions
8
Cooch Behar9 seats | Rajbongshi SC | Border
~1.5L
HIGH
9
Kolkata11 seats | Bhabanipur 47K alone
~1.3L
HIGH
10
Howrah16 seats | Uluberia belt
~1.2L
HIGH
11
Dakshin Dinajpur6 seats | Border; mixed Muslim
~0.7L
MED
12
Purba Bardhaman16 seats | Moderate SIR
~0.6L
MED
13
Alipurduar5 seats | ST tribal belt | Border
~0.4L
MED
14
Jalpaiguri7 seats | Rajbongshi SC belt
~0.4L
MED
15
Other DistrictsHooghly, Medinipur, Purulia etc.
~1.0L
LOW-MED
District Deletions Seats SIR Level Muslim % Muslim Decisive Matua/Rajb. Border Worst-hit Seat
Murshidabad ~4.5L 22 V HIGH 67% YES Partial Jangipur (flipped)
N 24 Parganas ~3.5L 33 V HIGH Mixed Partial Matua Yes Baduria / Basirhat
Nadia ~3.0L 17 V HIGH ~45% Partial Matua Core Partial Ranaghat (78% del.)
Malda ~2.5L 12 V HIGH 51% YES Partial Mothabari (37K)
S 24 Parganas ~2.5L 31 V HIGH ~35% Partial No Metiaburuz (25K)
Uttar Dinajpur ~2.0L 9 V HIGH 50% YES Yes Goalpokhar (30K)
Birbhum ~1.8L 11 HIGH ~40% Partial No Murarai / Nalhati
Cooch Behar ~1.5L 9 HIGH ~25% No Rajbongshi Yes Sitalkuchi (20K)
Kolkata ~1.3L 11 HIGH ~25% No No Bhabanipur (47K)
Howrah ~1.2L 16 HIGH ~25% No No Uluberia Purba
Dakshin Dinajpur ~0.7L 6 MED ~32% No Yes Harirampur
Purba Bardhaman ~0.6L 16 MED ~22% No No Ketugram
Alipurduar ~0.4L 5 MED ~14% No Yes Kumargram
Jalpaiguri ~0.4L 7 MED ~21% No Rajbongshi No Rajganj
Paschim Bardhaman ~0.4L 9 MED ~22% No No Asansol Uttar
Hooghly ~0.3L 18 LOW ~14% No No Singur
Purba Medinipur ~0.2L 16 LOW ~11% No No Nandigram
Paschim Medinipur ~0.2L 15 LOW ~10% No No Kharagpur
Darjeeling ~0.2L 6 LOW ~11% No Yes Siliguri
Bankura ~0.1L 12 LOW ~9% No No
Purulia ~0.1L 9 LOW ~9% No No
Jhargram ~0.04L 4 LOW ~7% No No
Kalimpong ~0.03L 1 LOW ~5% No Yes
*Click column headers to sort (preview only)
Sources: ECI Electoral Rolls 2026 | Census 2011 (district religion data) | Outlook India, The Federal, Swarajya — SIR impact analysis | Data as of April 2026
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