The zilla parishad members joined Trinamool Congress in the presence of party general secretary Mukul Roy, party sources said.
Newly-joined TC member Alema Nuri was elected sabhadhipati and Purnendu Dey became saha-sabhadhipati of the zilla parishad.
Nuri was an elected member of CPI-M and Dey defected from Congress.
Left Front was in power in the zilla parishad since the panchayat polls in July last year. The Left Front had 13 members, Trinamool Congress five members and Congress had 8 members in the 26-member zilla parishad.