In a sharp escalation of the Trinamool Congress (TMC) split, former West Bengal Chief Minister Mamata Banerjee on Thursday, 16 July issued a pointed ultimatum to wavering members of her faction — leave before July 21 if they intend to defect to the rebel group led by expelled TMC leader Ritabrata Banerjee. The warning came via a Facebook Live address, hours after former TMC legislator Tapas Chatterjee of the Rajarhat-Newtown constituency in North 24 Parganas publicly signalled his intent to switch sides.

The Ultimatum and Its Timing

Mamata Banerjee chose July 21 as the deadline deliberately. That date marks Martyrs' Day, an annual rally the TMC has held since its founding in January 1998, and she framed the occasion as a moment of personal and political rebirth — drawing a parallel to 1997, when she broke away from the Indian National Congress to establish the Trinamool Congress. She said those who remain with her after July 21 will be the party's real assets.

She said she respectfully requests those who feel compelled to quit under pressure from the BJP, the police, the Enforcement Directorate (ED), the Central Bureau of Investigation (CBI), and other agencies to make that decision before the rally. She urged them not to taint the party from within by staying on the fence.

What Mamata Said About Fence-Sitters

The former chief minister was categorical: a departure before July 21 would not weaken those who leave, she said, but lingering inside the party while secretly backing the rebel camp would damage the organisation she built. She added that she does not care about the headcount — loyalty, in her framing, matters more than numbers.

She also alleged that family members of the original Martyrs' Day victims are reportedly being pressured to attend the rival programme organised by the Ritabrata-led faction. She acknowledged they might attend, but said their souls would remain with her.

Rival Rallies in Central Kolkata

The split has produced a logistical standoff in central Kolkata. The Calcutta High Court has directed that the Mamata-led faction hold its Martyrs' Day rally on July 21 in front of the Birla Planetarium, not at the traditional venue near CESC House in the Esplanade area. The Ritabrata-led faction, meanwhile, plans a counter-rally on Jawaharlal Nehru Road, also in central Kolkata, on the same day.

The competing programmes on the same date and in the same part of the city raise the stakes considerably, with security and crowd management likely to be a flashpoint.

Background: The TMC Fracture

The current split traces back to the expulsion of Ritabrata Banerjee from the Trinamool Congress. His faction has since positioned itself as an alternative TMC platform, drawing in legislators and local leaders who are either disillusioned or, according to Mamata, acting under coercive pressure from central agencies. The defection signals from Tapas Chatterjee this week indicate the rebel camp is gaining traction ahead of the symbolic July 21 date.

How many members ultimately cross over before the deadline — and which faction commands the larger crowd on Martyrs' Day — will serve as the first real test of strength in this intra-party war.