India launched a revision of its voter rolls on Tuesday, expanding a contentious exercise that activists warn could fuel disenfranchisement in the world’s largest democracy.

The three-month voter registration overhaul — known as the Special Intensive Revision (SIR) — kicked off in 12 states and territories, many of which are slated to hold local elections next year.

Tens of thousands of election officials and nearly half a million volunteers will go door-to-door to help residents complete voter enumeration forms.

Officials “will help the elector fill the enumeration form, collect it and submit it”, Election Commission of India (ECI) chief Gyanesh Kumar told reporters while announcing the exercise.

Earlier this year, the ECI conducted a similar revision in the eastern state of Bihar, home to more than 130 million people, ahead of its state elections beginning November 6.

The process led to the exclusion of around 6.5m names, which the ECI said was necessary to prevent the inclusion of “foreign illegal immigrants”.

Members of Prime Minister Narendra Modi’s Hindu nationalist Bharatiya Janata Party (BJP) have long claimed that undocumented Muslim migrants from neighbouring Bangladesh have fraudulently registered as voters.

Critics, however, argue that stringent documentation requirements could result in large numbers of Indian citizens being wrongly removed from the rolls.

Activists have reported cases of living voters declared dead and entire families being struck off draft lists.

In August, India’s Supreme Court eased some concerns by ruling that the widely used biometric-linked Aadhaar identity card could be accepted as valid documentation for the process.

The latest SIR drive will cover major states, including Uttar Pradesh — India’s most populous state with about 199m people — as well as West Bengal with 91m, Tamil Nadu with 72m, and Kerala with 33m, according to the 2011 census.

Several rights groups and opposition parties have filed legal challenges.

Tamil Nadu Chief Minister M.K. Stalin, whose party filed its opposition in the Supreme Court on Monday, said the exercise was a “mere trick to delete the names of genuine voters”.

“Voting is the body and soul of democracy, and that right is facing a threat,” he told opposition parties on Sunday.

The final electoral roll is expected to be released on February 7, 2026.