Mamata Faces New Challenge as Santanu Sen Resigns from TMC Post After Kakoli Ghosh Dastidar

Santanu Sen has put in his papers as TMC's national spokesperson, and he is making no bones about it: it's a matter of principle. He comes on the heels of Kakoli Ghosh Dastidar's departure, and with these resignations, you can see the kind of headwinds Mamata Banerjee's party is up against after such a heavy loss at the polls.

It is the second time in as many days a senior figure has walked out, and it has only added to the restlessness in the Trinamool Congress. The pressure is on for Banerjee. Dr Santanu Sen, an ex-Rajya Sabha MP, made good on his exit from the national spokesperson role on 28 May 2026, right after Ghosh Dastidar left her post in the women’s wing.

You have to put these moves in context: they are what happens when you lose power after 15 years. It has thrown the party’s hierarchy and its line of communication into disarray. For now, both the TMC’s public face and its women’s arm are in some limbo.

Resignation that challenges the party’s moral stance

In a letter to the president, Dr Sen made it clear he was done with having to put a good word in for what he termed ‘immoral acts’. He has taken his share of flak in the past for standing by the party on hot-button issues, but this time he says he is bowing to the will of the voters.

His decision is tied to the kind of allegations that have been the talk of the town in Bengal since 2024. The letter makes mention of the 2024 RG Kar rape-murder case, for one, and the wider issue of corruption.

He puts down the matters he feels have eroded the public’s faith like this:

– RG Kar case

– Abhaya case

– Cash for job

‘When the people of Bengal have turned their back on us for all this… I can’t in good conscience be your spokesperson any more,’ is how he put it. He has asked for his resignation as ‘All India Spokesperson of the Trinamool Congress’ to be put to rest and accepted.

A second senior exit in 24 hours

Just before him, TMC MP Kakoli Ghosh Dastidar stepped down as head of the All India Trinamool Mahila Congress. She wrote that the party had not come to her defence when she was put upon by a colleague in the Rajya Sabha, a veiled dig at Banerjee.

Banerjee had already seen fit to make herself the chief whip in the Lok Sabha, taking over from Ghosh Dastidar. It is a sign of the distance that has opened up between some of the old guard and the ones calling the shots now.

Fault lines widen with complaint against Kalyan Banerjee

Then there is an internal tussle over a complaint lodged against Kalyan Banerjee. It is another layer to the current unrest, which is rife with resignations, shuffling of roles and claims of bad behaviour. It all points to a party that is having to work hard to keep its house in order.

Defeat reshapes TMC’s power and narrative

None of this is happening in a vacuum. The West Bengal Assembly elections of 2026 were a drubbing – 80 of 294 seats is not what you call a mandate. It has put an end to 15 years in charge and forced a rethinking of how the organisation operates and presents itself.

The figures don’t lie: the BJP took 207 of the 293 seats that were in on May 4, even the Falta seat where there was a repoll on the 21st. It is a stark change in what the voter wants, and it is putting a fine point on the need for the TMC to get its act together.

Sen has made a point of tying his leaving to the mood on the ground. By bringing up the RG Kar and Abhaya cases, he has made probity and how the party is run the topic of the day for anyone talking about the TMC’s future.

Immediate implications and what to track

With one thing after another, and complaints still in the air, there are some hard questions to be answered. The party will have to show some steadiness in how it talks to the outside world and be more open about what is going on within.

Here is what you are looking at in the near term:

– No more of the national spokesperson’s take in the media

– A void at the top of the women’s wing

– How well the party can police its own

For Banerjee, it is a two-pronged problem: get control of the message after a stinging result and put some trust back in the leaders who are openly wondering where the party is heading. What the TMC does from here will tell you if it can be a force in the opposition or just a memory for those who have had enough.

In the end, Sen wanted a clean break. He has cited the people's verdict and asked for his resignation to be honoured. For a party that has to face a new map, that is the measure of everything they do from now on.