With the election of Bhattacharjee, the number of women councillors rose to 20 in the 35-member AMC, which was constituted by the then royal dynasty in 1871.
Bhattacharjee was elected to the AMC as a nominee of the Communist Party of India-Marxist (CPI-M), defeating her nearest Congress rival Gautam Ghosh by a margin of 1,021 votes.
The by-poll for the AMC vacancy was held Monday following the death of civic body chief Sankar Das. He died in New Delhi Feb 10.