Mamata Banerjee leads by more than 31,000 votes after 10 rounds of counting.
Sobhandeb Chattopadhyay, who vacated the seat for the TMC supremo, won by a margin of 28,719 votes during the assembly polls.
Celebrations begin outside Mamata Banerjee's residence
All eyes are on Bhabanipur in West Bengal from where CM Mamata Banerjee needs to win to retain her chair.
Counting of votes for byelections to four assembly constituencies – three in West Bengal and one in Odisha -- commenced at 8am on Sunday and is currently underway. The three assembly constituencies in Bengal are Bhabanipur, Jangipur and Samserganj, while the one in Odisha is Pipili.
All eyes, however, are on Bhabanipur from where West Bengal CM and Trinamool Congress (TMC) chief Mamata Banerjee is in the fray. Banerjee, who lost to Bharatiya Janata Party's (BJP) Suvendu Adhikari in the assembly elections in March-April, needs to win to retain her chair. The BJP has fielded Priyanka Tibrewal against her.
Bypolls to all four constituencies took place on September 30.