Former Gorkha Janmukti Morcha (GJM) MLA Rohit Sharma also joined Mamata Banerjee's party.
Months ahead of the Gorkhaland Territorial Administration (GTA) election, former GJM leader Binay Tamang, who had quit the hills-based party earlier this year, joined the ruling Trinamool Congress on Friday.
Former Gorkha Janmukti Morcha (GJM) MLA Rohit Sharma also joined Mamata Banerjee's party.
Mr Tamang and Mr Sharma were handed over Trinamool flags by state ministers Moloy Ghatak and Bratya Basu.
When asked about his stance on the Gorkhaland statehood issue, Mr Tamang said the development of Darjeeling and Kalimpong hills is his top priority.
"Development of the hills is my top priority. The BJP is trying to use the statehood issue to fool the people of Darjeeling and Kalimpong districts. Since 2009, they have been saying that they support the Gorkhaland demand but have not done anything towards it," he said.
Mr Tamang, who had broken away from Bimal Gurung-led GJM in 2017 and led a faction of the party, quit the hills-based outfit in July this year.
Election to the 45-member GTA is likely to be held early next year. The last election to the semi-autonomous council was held in 2012.
Mr Tamang's joining the Trinamool at a time when a section of BJP leaders have renewed the demand for Gorkhaland state and also sought to carve out north Bengal as a centrally-administered Union territory, citing disparity in development and injustice to the people of the region.
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