Mr Chauhan was the minister for forests in the BJP government headed by Yogi Adityanath.
OBC leader and former Samajwadi Party MLA Dara Singh Chauhan on Monday joined the BJP at the party office here.
Mr Chauhan joined the party in the presence of Deputy Chief Ministers Keshav Prasad Maurya and Brajesh Pathak, Uttar Pradesh BJP chief Bhupendra Singh Chaudhary and ministers Girish Yadav and Baldev Singh Aulakh.
Earlier in the day, Mr Chauhan met Speaker of the Uttar Pradesh Legislative Assembly Satish Mahana at the latter's office and handed over him his resignation letter.
On Saturday, Mr Chauhan, who was the MLA from Ghosi in Mau district, had tendered his resignation from the UP Legislative Assembly.
An Other Backward Classes (OBC) leader, Mr Chauhan was the minister for forests and environment in the previous BJP government headed by Chief Minister Yogi Adityanath. He resigned from the Council of Ministers on January 12, 2022.
Mr Chauhan represented the Madhuban Assembly constituency in Mau district from 2017 to 2022. He also represented the Ghosi seat in the 15th Lok Sabha for the Bahujan Samaj Party (BSP). In the 2014 Lok Sabha polls, he was defeated by BJP candidate Harinarayan Rajbhar by more than 1.4 lakh votes.
Mr Chauhan had joined the BJP in 2015 and was appointed the party's OBC Morcha president and fielded from the Madhuban Assembly constituency.
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