The timing was harsh and hard. As Trinamool Congress supremo Mamata Banerjee was sitting in the morning of June 8, 2026 in the Constitution Club of India in New Delhi, where she was at a INDIA bloc strategy meeting, her party was falling apart not in some far-flung district, not in a village booth but in Parliament, just a few hundred metres away.

Twenty Lok Sabha MPs led by TMC Chief Whip Kakoli Ghosh Dastidar wrote to Lok Sabha Speaker Om Birla formally declaring their support for the BJP-led National Democratic Alliance (NDA), causing a split in the TMC's parliamentary unit that severely undermined Mamata Banerjee's authority. The letters were not a surprise to those in the know. They came as a testament to something that had been simmering for months.

The turning point letter

The development was confirmed by the chief whip of the TMC in the Lok Sabha, Kakoli Ghosh, who has informed exclusively that it was the outcome of a long discussion among the party members in the House saying: "Nearly 20 of us, including myself, have decided to write to the Speaker and formally express our desire to join the NDA.

Her remark was really quite astounding. The chief whip of the party the man who is constitutionally responsible for mustering the party on its feet in Parliament is announcing a revolt. Her dismissal from the TMC's Mahila wing was arbitrary and unilateral, she said, the last straw in a long string of complaints by her.

Sources in the dissident camp said that the MPs have decided not to resign from the TMC or join the BJP at the moment. Rather, they would be an independent parliamentary group, which would back the NDA a ploy that would guarantee their protection under the anti-defection law. The arithmetic in the law here is intentional and designed. Presently, there are 28 Lok Sabha MPs in the TMC, one of whom died, Basirhat MP Haji Nurul Islam. Favored by 20 MPs would comfortably exceed the two-third requirement for protection under the anti-defection law. That is to say, they have not only revolted, but they have revolted in the most defensible manner, and by the advice of a man, whose advice must have been obtained with some knowledge.

The fire which originated in Kolkata

This parliamentary explosion came out of a vacuum. It is the logical result of an electoral disaster that took place in West Bengal not so long ago upstream.

In the April 2026 assembly elections in the state, the BJP secured a historic victory, marking the first time in nearly 50 years that the ruling party at the centre has won the elections in the state. The BJP secured 207 out of 294 seats in the assembly with 46 per cent votes, while the ruling TMC got 80 seats and 41 per cent votes.

One of the last bastions of opposition on the map tumbled with the anti-incumbency sentiment, the Hindu consolidation and the assurance of changing the face of the State of West Bengal. The BJP's campaign messaging also implied ₹3,000 a month for women, as compared to the ₹1,500 a month given under the Lakshmir Bhandar scheme of the TMC, which took a toll on Mamata's popularity among women who are the backbone of her electoral victories.

The attack on Mamata was personal and political. She was portraying herself as the final bastion of opposition to BJP's victory of India. For now, that argument is in shambles.

The news was broken just days after the TMC leadership was setback in West Bengal assembly when 58 of its 80 MLAs rejected the party high command's decision to appoint veteran leader Sovandeb Chattopadhyay as Leader of the Opposition (L-O) and chose expelled MLA Ritabrata Banerjee instead. Even in the aftermath of 80 seats, the party failed to keep its own legislators on a basic procedural issue.

Sukhendu Sekhar Roy: the dam breaks

The man behind the parliamentary dam buster is senior Rajya Sabha MP Sukhendu Sekhar Roy who was watching his influence waning within the party for a long time. Ever since Mamata promoted Abhishek Banerjee into a top leadership position, Roy had been feeling sidelined. He had just cautioned that the unrest witnessed in the state assembly would soon spread to the Parliament.

So when he did act, he did it loud. Roy, in a trenchant resignation letter to party chief TMC's Mamata Banerjee, pointed out that the party was running a "rampant corruption, extreme oppression of women and utter failure in governance". He also referred to the "severe anarchy" prevailing in the state in various fields like education, healthcare, industry, employment and law and order in West Bengal.

Roy quit his Rajya Sabha seat and had been accepted by Vice President CP Radhakrishnan. Then 13 TMC Lok Sabha MPs called on Roy at his Delhi residence and later all the MPs had a meeting with Union Minister Bhupender Yadav, who was also present at the meeting with West Bengal Chief Minister Suvendu Adhikari. The choreography of the meeting between the sitting Union Minister, the new West Bengal CM and over a dozen of TMC MPs made it abundantly clear what is going on.

The rebel camp's move coincided with Mamata Banerjee and General Secretary Abhishek Banerjee being in Delhi for the INDIA bloc meeting. Sources suggest that some leaders, who had earlier been close to her, are not even picking her calls. But, before departing for Delhi, Mamata personally met some of the councillors of the Municipality and requested them to remain with the party.

The Abhishek factor: dynasty, resentment, and the accelerant

Beneath the formal complaints of corruption and governance is a much more basic and primal one: the growing centralization of party power around Abhishek Banerjee, Mamata's nephew. Abhishek has been the Leader of All India Trinamool Congress in Lok Sabha since August 2025 and National General Secretary since 2021. To veteran leaders who worked the party from the ground up for years, witnessing their nephew progressively taking over control of every decision, at the tender age of 38, has been quietly corrosive to morale.

Roy wasn't the only one who was upset. This is the theme of sidelining, arbitrary reshuffles and ignoring party mechanisms in favour of Abhishek's preferences that is coming out in the testimonies of those who are walking out. The dismissal of the chief whip from the chair of the Mahila wing without consulting her, is a small but symptomatic act in a larger culture of unilateralism from the top that has robbed the party of its unity.

Economically for Bengal this means that the locals will be able to buy food at a lower price.

The political turmoil comes at a serious economic juncture for Bengal, as a state, which can hardly afford of further such unstable churning. As per the current estimates, at 12 per cent average annual growth rate from the previous year, the Gross State Domestic Product (GSDP) of West Bengal is expected to be around ₹20.32 trillion (US$ 236.56 billion) in 2025-26, and it is the sixth largest state in India in terms of GSDP.

The state's nominal GDP growth was 11.85 per cent and real GDP growth was 8.62 per cent in 2025-26, of which 53 per cent was contributed by services, nearly 30 per cent from industry and 17 per cent from agriculture.

But the structural problems are well known. India's state contribution in national GDP has dropped from 6.8 per cent in 1990-91 to 5.8 per cent in 2021-22 while its per capita income is 20 per cent lower than the national average. FDI inflow of West Bengal stood at around ₹15,256 crore during the period of October 2019 and June 2025, which is much lower than its economic weightage compared to other states such as Gujarat, Karnataka or Telangana etc.

Investment attraction and industrial development have become the main part of the election agenda of the incoming BJP government in Nabanna under Suvendu Adhikari. The BJP's offer of transformative economic governance wasn't a coincidence in messaging: it was a marketing ploy for a state that has seen its economic standing erode over many decades of political upheavals and governance issues. The key economic challenge Bengal is now grappling with is whether the new dispensation can convert that promise into investment flows. In the short term, however, political uncertainty at the parliamentary level affects investor confidence and federal funding.

The fiscal deficit in West Bengal is to be reduced to 3.6 per cent of GSDP and revenue deficit is to be reduced to 1.7 per cent a budget which is highly dependent on central transfers, with 54 per cent of revenue receipts coming from the centre, of which 40 per cent is the state's share in central taxes. A party whose parliamentary cadre is leaving it is a party with dwindling power in the corridors of New Delhi, and that means less fiscal space for Bengal at the centre.

What this translates to in the larger picture for the INDIA bloc?

June 8 is a cruel irony on the optics. Mamata was present at the INDIA bloc meeting where, according to reports, she informed her allies that "she now has the time and the alliance can avail her services if it wants". Her MPs at the time were sending the government she had fought for years the signal that she was supporting it.

It was during the meeting of INDIA bloc that it was suggested to establish state-level and national-level coordination committees for better coordination among the alliance partners, sources said. But with a leadership team that is breaking up, the opposition leader is at a much weaker position in those talks. Other INDIA bloc partners Congress, Samajwadi Party, DMK etc. will silently bring down the weightage of TMC's voice.

The big question raised by the TMC's collapse is that of the sustainability of personality-centric regional parties in the current Indian politics. TMC has never been a party, but an extended political project of Mamata Banerjee, around her charisma, grievance politics and her absorbing quality of attracting everyone in her orbit. After each major electoral debacle, when the orbiting force subsides, the centrifugal forces can no longer be restrained.

Can one ever come back?

Five of the rebel MPs, at least, will come back to the fold, TMC sources said. Roy himself explained he had rejected an invitation to join the BJP, suggesting not all dissenters are to be counted as defectors. Some will be watching, waiting and negotiating. Politics is not permanent in India and there are numerous examples of parties that seemed to be in a death spiral but made it back in Bengal's history.

But structural problem is more difficult to solve than one by one relationships. When the chief whip writes to the Speaker to lend his support to the rival alliance, when a senior MP from the Rajya Sabha quits referring to it as a corrupt organisation and when MLAs defy the high command even in opposition, that's not a party with a messaging problem. It's a party that has lost its legitimacy. The challenge now for the TMC is not to win the next election. It's about staying alive through the next Parliament session as a political party.

The most difficult task for Mamata Banerjee may be to realize that she is forced to start from a place she has never been before: having lost Bengal and her own people.