The scams involving ponzi firms such as Saradha and Rose Valley defrauded millions of small investors of tens of thousands of crores. Those who ran the firms had close ties with politicians and several of Mamata’s own men have been in the dock. Some of them, such as former minister Madan Mitra and member of parliament Tapas Paul, have spent jail time for their alleged links to them.

The CBI too has a lot to answer. Its decision to question the Kolkata police commissioner over some reported missing files related to the chit fund probe months before the general elections raises several questions. Having done precious little earlier, the alacrity it displayed by sending a team to the police commissioner’s home days after Mamata hosted an opposition rally in Kolkata in a direct challenge to Prime Minister Narendra Modi makes its motives a suspect.

Moreover, Bengal wasn’t the only state where chit funds operated. Neighbouring Odisha too was rocked by similar scams, but the CBI has visibly been less proactive in the state. Though members of the ruling Biju Janata Dal have been linked, the probe in Odisha has made little progress, opening the central agency to accusations that it was dragging its feet because the BJP is hoping to court chief minister Naveen Patnaik with an eye on post-poll alliances.

There is more to put the motives under cloud. Mukul Roy, a former union minister and once a close aide of Mamata, was under the scanner for his links to Saradha and there was talk of his imminent arrest. But Roy continues to be a free man, having switched sides. He is now a top-ranking BJP leader of Bengal tasked with leading the party’s offensive to unseat Mamata. The Bengal chief minister is therefore not entirely unjustified when she challenged the CBI’s attempt to go after her men while letting off the likes of Roy. Never shy of rhetoric, Mamata has seized upon the opportunity to attack Prime Minister Modi. “Modi has gone mad,” she told a rapturous audience of party faithfuls from her dais at the dharna site in downtown Kolkata.

With a slew of accusations flying thick and fast, what Mamata has done now by going on a dharna in protest against the CBI’s move to question the police commissioner is what she does the best. Having cut her teeth in politics with street protests against the then Communist dispensation in her earlier years, she has hit the streets again to orchestrate support in her tirade against Modi. It could help her in many ways: one, she could position herself as the principal rival to Modi and burnish her credentials as an aspiring prime ministerial candidate. Two, by portraying the CBI as a political tool unleashed against her, she can cover up the misdeeds of her aides in the dock over the chit fund probe. It would be easier to explain away their alleged involvement as nothing but political vendetta.

If the BJP’s plan was to exploit the CBI to pressurise Mamata before elections and put her under siege, the execution hasn’t gone according to plans. The mercurial Mamata has gleefully accepted the challenge.

Of course, the chief minister will talk about how an autocratic Central government under the BJP is out to colonise the states by destroying federalism. She will also undoubtedly invoke Bengali pride, projecting herself as someone who is being wronged. But make no mistake, the high voltage drama playing out in Kolkata has more to do with political manoeuvring and less with probity. Both sides are out to score political points and if the slugfest is leading to a constitutional crisis, so be it.