Bengal poll arithmetic: Why TMC wants Left, Congress to do well

In 74 of these seats, the TMC was victorious, while in 43, the BJP was. It was apparent that in its crushing defeat, the Left-Congress combine had ended up splitting the anti-TMC vote. The Morcha’s only seat was Bhangar, won by the ISF, with both the Left and the Congress clocking zero.

Even when the ISF is excluded, the Left-Congress vote alone exceeded the winning margin in 108 constituencies. In effect, a formation that was electorally marginal remained arithmetically central.

This time, the TMC is not just focused on retaining its own support base, it is also keenly watching the performance of the Left and the Congress. As a TMC leader told The Indian Express ahead of the polls, “We want the Left and the Congress to contest well. That will be to our advantage.”

Why Phase 2 sharpens the impact

Of these 117 constituencies, 54 go to the polls in Phase 2, which covers south Bengal’s urban and industrial belt comprising Kolkata, Howrah, Hooghly, North and South 24 Parganas, and parts of Bardhaman and Medinipur.

This geography matters. Unlike Phase 1, which covered north Bengal, Jungle Mahal and the border districts where contests have become sharply polarised, Phase 2 moves into urban, peri-urban spaces and industrial corridors, regions where the Left historically had deeper organisational roots through trade unions, municipal networks, and urban cadres. The region is more influenced by urban governance, jobs, and local corruption narratives, something that suits the Left and something it is also trying to tap into.

Also, a disproportionate share of these “spoiler” seats lies in south Bengal, where the TMC had done very well in 2021. For example, in Diamond Harbour, the CPI(M) secured around 17% of the vote, while the TMC’s victory margin was only about 7%. In Howrah Uttar, the Left’s roughly 5% vote share still exceeded the TMC’s narrow 3% winning margin. In Uttarpara, the CPI(M) polled about 21%, higher than the 18% margin by which the BJP lost to the TMC.

A similar pattern was visible elsewhere. In Singur, the CPI(M)’s 14% vote share was larger than the TMC’s 12% margin. In Chandannagar, it secured around 19%, compared to the TMC’s 17% winning margin. In Durgapur Purba, the Left polled about 15%, while the TMC won by just 2%. In Pandua, too, the Left’s vote share of nearly 19% exceeded the margin of victory.

In Bardhaman Uttar, the CPI(M)’s roughly 12% vote share was higher than the margin by which the BJP lost to the TMC. In Sonarpur Dakshin, the CPI polled about 14%, while the TMC’s margin stood at around 11%.

Even in constituencies where the Left-Congress combine did not directly exceed the victory margin, its presence remained substantial. The CPI(M) secured close to 13% in Howrah Dakshin and over 15% in Sankrail, while the All India Forward Bloc polled around 14% in Shibpur. In Panchla and Uluberia, candidates of the ISF-backed RSSCMJP symbol secured about 16% each. In Jadavpur, the CPI(M) polled nearly 27%, pushing the BJP to third place.

This underlines that any shift in Left-Congress vote shares can impact the outcome of the polls this time. If it stabilises, or even rises marginally in select constituencies, it could divide the anti-TMC vote, undercutting the BJP’s ability to consolidate Opposition support.

But the reverse is also possible. A large portion of the Left’s traditional vote had shifted to the BJP between 2016 and 2021. If that erosion continues, the BJP could benefit from sharper consolidation.

In a phase where margins are expected to be tight, even a 2–3% shift could prove decisive. The Sanjukta Morcha garnered close to 9% votes in the 2021 polls.

A party in transition

After its zero-seat performance in 2021, the CPI(M) has attempted a recalibration rather than a full-scale comeback.

The party has foregrounded younger leaders from its student and youth wings, sought to rebuild its booth-level presence, and expanded its digital outreach. Its campaign has centred on economic issues such as jobs, industrial decline, and corruption, while framing both the TMC and BJP as inadequate alternatives.

CPI(M) Central Committee member Sujan Chakraborty said, “People are annoyed with Trinamool. People have lost confidence in the party. So people are looking for an alternative. Earlier, people were looking at the BJP as an option. But the way the BJP is moving (in the campaign), it is apparent that it is not an option. Modi and Shah have not even held a meeting in Bhabanipur. They are camping in Kolkata.”

Chakraborty insisted that the Left support was on the rise. “The participation of people in Left rallies is huge. There is a wave of red flags. People’s attitude is quite clear from that. In the panchayat elections, the Left did better than the BJP. This time, too, people’s intentions are the same. People are interested in going along with the Left,” he said.

Yet, despite these efforts, the constraints remain stark. The bipolar contest between the TMC and the BJP continues to dominate voter perception and the Left’s organisational erosion, particularly outside select urban and industrial pockets, has not been reversed.

Also, the Congress is contesting independently this time, weakening the possibility of a consolidated third bloc.