Former Mayor of Bidhannagar and TMC MLA Sabyasachi Dutta joined BJP on Tuesday.
He joined BJP in the presence of party president Amit Shah.
On Monday, Dutta had said that he will be joining the party in the presence of Amit Shah.
"I will be joining BJP tomorrow at Netaji Indoor Stadium in Kolkata in the presence of Union Home Minister Amit Shah," Dutta had said on Monday.
Last month, former Kolkata Mayor and TMC MLA Sovan Chatterjee joined the BJP.
In this year's Lok Sabha elections, the BJP made deep inroads in West Bengal, winning 18 out of 42 parliamentary constituencies while the TMC managed just 22, 12 less than it had won in the 2014 polls.
Since then, several TMC leaders including Biswajit Das Tusharkanti Bhattacharya, Monirul Islam and Sunil Singh have joined the BJP.
The Mamata Banerjee-led party has also lost control over five civic bodies of Bhatpara, Halisahar, Kanchrapara, Naihati and Garulia.