The action taken against Trinamool Congress MLA Shikha Mitra —suspending her from the party, hours after she spoke to journalists on the recent ruckus in the West Bengal Assembly, despite instructions from the party not to speak to the press —was striking both in its speed and severity, particularly as it came in the wake of more serious transgressions from senior leaders of the party going unpunished.

Her comment that the violence in the Assembly was condemnable regardless of which party was involved earned her a suspension at a time when Cabinet Minister Rabindranath Bhattacharya’s allegations of “extortion” under the ‘auspices’ of the Trinamool Congress that Chief Minister Mamata Banerjee was aware of and the Government Chief Whip Shovandeb Chattopadhyay’s threats to quit the party have not earned them a public censure so far. It is another matter that Jadavpur MP Kabir Suman has for nearly three years defied the party line on several issues without facing any disciplinary action.

Ms. Mitra’s direct criticism of Chief Minister’s Mamata Banerjee’s style of running her government in July this year failed to precipitate any action against her then. Was it her decision to file a defamation suit against the party’s secretary general and State Minister for Industries Partha Chatterjee last month that did her in?

Or is Ms. Mitra’s suspension intended to be a deterrent at a time when an atmosphere of dissent hangs over the party?

Mr. Bhattacharya’s rebellion followed a major Cabinet reshuffle on November 21 in which eight new faces were inducted, one Minister dropped and the portfolios of eight Ministers shuffled.

Mr. Bhattacharya, who is a three-time MLA from Singur himself, was shifted from the Agriculture Department to Statistics and Programme Implementation. He responded by refusing to attend his new office and then raised the stakes by levelling allegations of extortion by party workers in Singur, admitting that it occurred “under my very nose.”

His remarks brought to the fore a split in the ranks within the Trinamool Congress in Singur showing the newly-appointed Minister of State for Agriculture and MLA from neighbouring Haripal, Becharam Manna, in very poor light. The public anger in Singur — the epicentre of Ms. Banerjee’s movement against land acquisition — was evident when Mr. Manna faced protests from villagers.

But far more damaging was Mr. Bhattacharya’s assertion that Ms. Banerjee was aware of the ongoing nefarious activities.

Matters in Singur were far from resolved when the focus shifted to Kolkata. This time Mr. Chattopadhyay — a senior trade union leader who has already been sidelined from the party’s labour wing — threatened to quit the party.

Mr. Chattopadhyay felt so humiliated when he was heckled by members of the party’s student wing the Trinamool Congress Chatra Parishad that he publicly said, “I will reconsider my stay in the party if it fails to take action on the matter.”

His remarks, made a week before the Winter Session of the State Assembly, spurred rumours that he was likely to lose the post of the Government Chief Whip, but again, he is yet to face disciplinary action.

Dissent within the rank and file of the Trinamool Congress emerged within months of the party coming to power in the watershed Assembly elections in 2011. But recent events are certainly a cause for alarm for the party because this time it is senior leaders and those who have been with the party since its inception have joined the ranks of the discontented.