Abhishek Banerjee, the Trinamool Congress leader in the Lok Sabha, was reportedly allotted a seat behind his former colleague Sudip Bandyopadhyay on the first day of the Monsoon Session of Parliament on Monday, 20 July — a seating shift that encapsulates the dramatic collapse of Trinamool's parliamentary standing in a matter of weeks.

The demotion in seating follows a major split in the Trinamool Lok Sabha party, in which 20 MPs — including Bandyopadhyay and Kakoli Ghosh Dastidar — broke away and merged their faction with the little-known National Citizens Party of India (NCPI). The Lok Sabha Speaker has since granted the merged group separate seating, based on the Tenth Schedule of the Constitution and established Parliamentary precedents. The NCPI bloc now commands 20 members, against Trinamool's residual strength of eight.

From Growth to Fracture: Trinamool's Parliamentary Journey

Trinamool Congress's trajectory in Parliament has been one of sharp ascents and, now, a steep fall. The party grew from single digits to 19 seats in the 2009 Lok Sabha election and 34 seats in 2014, riding the political wave engineered by party supremo Mamata Banerjee. At its peak, it demanded — and received — its own Parliamentary party office in what is now called Samvidhan Sadan, at the time displacing the Communist Party of India (Marxist) (CPI(M)), which had long held an office on the top floor of the old building.

In the 2024 general elections, Trinamool won 29 seats. However, internal fractures deepened following setbacks in this year's West Bengal assembly election. One seat also remains vacant following the death of a sitting MP, leaving the parent party with eight members in the lower house.

The Legal Architecture Behind the Split

The rebel lawmakers' merger with the NCPI was carefully structured to exploit a specific provision of India's anti-defection law. Introduced through the 52nd Amendment, the law ordinarily disqualifies legislators who voluntarily give up membership of their original party. However, Paragraph 4 of the Tenth Schedule provides an exemption for mergers: disqualification does not apply if at least two-thirds of the members of the original legislative party agree to merge with another party.

With 20 of Trinamool's 29 elected MPs joining the breakaway faction, the rebel group comfortably cleared the two-thirds threshold of the parent Parliamentary party's current strength, insulating them from automatic disqualification. Merging with the NCPI — a party recognised by the Election Commission of India (ECI) but one that had never contested a Parliamentary election — also sidestepped a potentially protracted legal battle over the Trinamool name, election symbol, and party constitution.

Speaker's Authority and Pending Petitions

The Trinamool leadership, including Abhishek Banerjee, has submitted disqualification petitions under the Tenth Schedule. However, the Lok Sabha Speaker holds ultimate authority over the recognition of Parliamentary groups and seating arrangements. While the political and moral legitimacy of the manoeuvre is fiercely contested by the Opposition, the procedural steps reportedly align with statutory provisions governing party splits and legislative mergers.

Impact on Parliamentary Arithmetic

The realignment significantly strengthens the National Democratic Alliance (NDA)'s grip on the lower house. The NCPI, overnight transformed into one of the prominent blocs in the Lok Sabha, is now a key ally of the Bharatiya Janata Party (BJP)-led ruling coalition. Critics argue the move further erodes the effective opposition presence in Parliament. For Trinamool, the eclipse of its Lok Sabha group by a bloc that did not exist as a parliamentary force until recently marks a historic low — and a cautionary tale about the fragility of parliamentary parties built around a single dominant personality.

How the Speaker rules on Trinamool's disqualification petitions will be the next critical development to watch.