Kolkata: In a big jolt to West Bengal`s ruling Trinamool Congress ahead of the Bangaon Lok Sabha by-polls, minister Manjul Krishna Thakur Thursday quit and joined the BJP, calling Chief Minister Mamata Banerjee "unprincipled" and the party unfit for any "good and educated person".

Thakur, who held the refugee, relief and rehabilitation portfolio in the Banerjee cabinet, joined the Bharatiya Janata Party (BJP) along with his son and panchayat functionary Subrata Thakur. The Trinamool reacted by expelling both the deserters and naming the duo`s bitter rival Mamata Thakur as party candidate for Bangaon.

By roping in the sitting minister, who is also the younger son of the influential Matua community leader Binapani Debi Thakurani (Baroma), the BJP has got its biggest political catch in the eastern state where it has been traditionally weak, but seemingly making inroads over the past eight months.

The party bagged two seats in the Lok Saha contest, and then got its first legislator in 15 years by winning Basirhat (South) by-poll last September, as it tries to project itself as the alternative to the Trinamool.

Announcing his resignation from the ministry and the party and formally joining the BJP in the presence of its state president Rahul Sinha, Thakur accused Banerjee of indulging in "unprincipled activities" and acting as per her whims.

The condition in the Trinamool is such now that no "good and educated person can remain in that party", he added.

"I was never allowed to work in my department. There was too much of factional feuds... I couldn`t work for the Matua community.

"This party is bereft of any ideals. You know about Saradha (chit fund scam) and other issues... people ridicule us on the streets," said Thakur, who also described the chief minister as "conceited".

The Matua community, comprising primarily low caste Hindu refugees from Bangladesh who are members of the Matua Mahasangh, commands nearly a crore votes in various Southern Bengal districts and plays a crucial role in determining the electoral fortunes in at least 74 of the state`s 294 assembly seats. It is almost a ritual for all parties to call on Baroma and seek her support ahead of every election.

Manjul Thakur`s elder brother Kapil Krishna, who won last year from the Bangaon Lok Sabha constituency, died recently, necessitating the Feb 13 by-polls.

There is much speculation that Subrata Thakur will be the BJP candidate from Bangaon.

The Trinamool hit back by giving the bypoll tickets to Kapil Krishna`s widow Mamata, engaged in a bitter feud with Majul Krishna to control the Matua community.

Trinamool secretary general Partha Chatterjee announced both "Manjul Krishna Thakur and Subrata Thakur have been expelled", and claimed its organisation won`t be affected in any way by their exit.

Attacking the minister, Chatterjee said why he has not resigned as a lawmaker if he was so concerned about ideology and morality.

Sinha however said the two Thakurs` joining has kickstarted the exodus from the Trinamool. "This is the first instance of a Trinamool minister joining the BJP by resigning from office. I had told you a few days back that a lot of Trinamool leaders, unable to work in the party with dignity, want to quit and join the BJP."

He claimed more Trinamool leaders would join the BJP this month.

"Twenty nine more Trinamool leaders want to join our fold. However, we will maintain a distance from those against whom there are allegations of cheating the poor people. We are happy there is not a single allegation of financial impropriety against Manjul," said Sinha.

Left Front chairman Biman Bose termed the development as "only the beginning" of the Trinamool`s disintegration. "Those who were attracted by the hoardings (about Mamata Banerjee being)... symbol of honesty, are now disillusioned. With the hoardings now having disappeared, they realised it was not true."

State Congress president Adhir Chowdhury said Banerjee was getting a taste of her own medicine. "It was she who had been shopping for MLAs and other leaders from opposition parties by using her money power. Now the BJP, which has more money power, is giving her back."