West Bengal Chief Minister Mamata Banerjee Friday filed her nomination papers for the September 30 Bhabanipur assembly by-poll.
The TMC supremo will be pitted against BJP's Priyanka Tibrewal and Left Front's Srijib Biswas.
The result will be declared on October 3.
Banerjee, who lost the election in Nandigram, has to win this by-poll to retain the chief minister's post.
Banerjee is a resident of Bhabanipur and had won the seat twice in 2011 and 2016.
She had contested from Nandigram in the April-May assembly poll this year against BJP leader and her former protege Suvendu Adhikari and lost.
After her defeat in Nandigram, Sovandeb Chattopadhyay, state cabinet minister and TMC MLA from Bhabanipur, vacated the seat to facilitate her return to the assembly from there.