Muhammad Daud Ali, a former Indian army technician, recently discovered that he was no longer a voter in his home state of West Bengal. His name - and those of his three children - had been struck off the electoral rolls despite valid documents, including his passport and service records. Only his wife remained on the list.

Ali, 65, and his children are among nine million voters - about 12% of West Bengal's 76 million electorate - who have been removed from the 2026 rolls as part of the Special Intensive Revision (SIR) exercise. Voting to elect a new state government will take place later this month in this eastern Indian state.

Of these nine million, more than six million names were struck off as absentee or deceased voters, while the fate of another 2.7 million - including families like Ali's - remains undecided and will be determined by tribunals.

Thirteen states and federally-administered territories have undergone the SIR process so far, but West Bengal is the only one where it was followed by an additional layer of special adjudication.

India's Election Commission says the revision is meant to weed out duplicate or outdated entries and add genuine voters. But the exercise has been mired in controversy and faced legal challenges ever since it was first held in the state of Bihar last year.

It has become particularly contentious in West Bengal, where the ruling Trinamool Congress party (TMC) is locked in a bitter standoff with the poll body.

Gyanesh Kumar, the chief election commissioner, has said the revision exercise's aim is to ensure a pure electoral roll with no eligible voters excluded and no ineligible persons included.

The tensions have been fuelled by remarks from political leaders, including from Prime Minister Narendra Modi, who have suggested in campaign speeches that the clean-up is aimed at identifying so-called illegal Bangladeshi infiltrators - a term the TMC says is being used to refer to Muslims. However, many Hindu voters have also been left out from the list.

India shares a 4,096km (2,545-mile) largely porous and partly riverine border with Bangladesh and a significant stretch of it runs through West Bengal. This has added a fraught political edge to debates over migration and voter rolls in the state.

West Bengal is also home to India's second-largest Muslim population, accounting for roughly 14% of the country's 172 million Muslims, according to the 2011 census.

Home to more than 70 million voters, the state has been governed by Chief Minister Mamata Banerjee's TMC since 2011, with Modi's Bharatiya Janata Party (BJP) as its main challenger.

With the fourth-highest number of India's parliamentary seats, West Bengal remains a key prize the BJP has yet to win. In the 2021 assembly polls, it secured about a quarter of the state's 294 seats.

Banerjee's party alleges the roll revision exercise has disenfranchised millions - particularly Muslims - to benefit the BJP, a charge both the party and the Election Commission deny.

After repeated legal challenges, the Supreme Court allowed the Election Commission to proceed with the April polls without settling all disputes over the deletions. As a result, the fate of 2.7 million voters remains undecided.

Political scientist Sibaji Pratim Basu argues that leaving out 2.7 million voters is an absurd proposition and a shame for democracy.

Yet federal minister Sukanta Majumdar from the BJP claims the revision is necessary to ensure only Indian citizens can vote, asserting that purging non-citizens was in the national interest.

The deletion of such a large number of names has sharpened concerns over errors, exclusion risks, and the criteria used to determine valid voters.

The impact of the overall revision has been uneven, with urban pockets experiencing sharp cuts, including up to 29.6% of voters struck off in Kolkata. In border districts with Bangladesh, primarily Muslim populations faced significant deletions, stoking further tensions.

As election day approaches, the unresolved fates of millions continue to loom over West Bengal's political landscape.