Agartala, Aug 24 : In a jolt for the opposition Congress in Tripura, its Working President and former minister Billal Mia, who resigned from the party on Wednesday, joined the ruling BJP on Thursday. The 63-years-old leader joined BJP at a function at Kulubari in Sepahijala district. Chief Minister Manik Saha, state BJP President Rajib Bhattacharjee, several ministers and senior party leaders greeted Mia, who was a leading Muslim leader of Congress. Mia in a letter to Congress President Mallikarjun Kharge on Wednesday said that he wants to quit from all posts and the primary membership of the party, which according to him, was his home for more than 40 years. The former Minister (1988-1993) was annoyed for not being nominated by the Congress in the February 16 Assembly polls and in the September 5 by-election to the Boxanagar Assembly constituency, a Muslim dominated seat. Political circles predict that Mia's joining into the BJP would boost the party's performance in the Boxanagar by-elections, which fell vacant after the death of sitting CPI-M MLA Samsul Haque, who passed away on July 19 after a cardiac attack. On the other hand, Tripura Pradesh Congress President Asish Kumar Saha on Wednesday expelled Mia from the party for six years for 'anti-party' activities. /IANS