Twenty of the Trinamool Congress's 28 Lok Sabha MPs wrote to Speaker Om Birla on Monday declaring support for the BJP-led NDA, a break that split the party's parliamentary strength in one stroke. Led by Kakoli Ghosh Dastidar, the MPs said they were forming a separate group, and the move immediately put the word rebel at the centre of the TMC crisis.

It was Mahua Moitra who turned the split into a public confrontation. On X, she singled out Yusuf Pathan, the Baharampur MP and former cricketer, and wrote: "Our district voted you in by a huge margin. Have some shame and some spine," adding that she had stood firmly with Mamata Banerjee. Her criticism landed on the same day the MPs made their break, giving the rebellion a face and a name rather than leaving it as a backroom manoeuvre.

Ghosh Dastidar said the decision came after consultations with fellow MPs and that the group had accepted the people's verdict. "We have accepted the people's verdict and believe our future political course should be aligned with the NDA," she said. The scale matters: 20 of 28 MPs is not a protest on the margins but a major rupture in a parliamentary unit that has long been one of the party's most visible national assets.

The break was also carefully worded. Sources in the rebel camp said the MPs did not plan to immediately quit the TMC or formally join the BJP, even as they intended to function as a separate parliamentary group while extending support to the NDA. That has made the move look less like a clean defection than a calculated attempt to stay inside the party's formal structure while shifting allegiance in practice.

That calculation points to the real stakes. The split is being viewed as an effort to shield the MPs from disqualification under the anti-defection law, and it echoes a separate legislative move just days earlier, when expelled MLAs Ritabrata Banerjee and Sandipan Saha claimed the backing of 60 legislators while reaffirming Mamata Banerjee as the party's leader. A letter signed by 58 MLAs also proposed Ritabrata Banerjee as Leader of the Opposition, showing that the pressure on the TMC is spreading beyond Parliament.

For now, the immediate question is not whether the MPs have signalled their drift to the NDA. They have. The question is whether they can keep their TMC membership, avoid a legal challenge, and still operate as a separate bloc without forcing a formal split. That is the next fight Mamata Banerjee's party has to answer, and it is already under way.