Samajwadi Party's Bihar unit president Ramchander Singh Yadav said the party was in talks with "like-minded" Nationalist Congress Party and the Left to contest the elections jointly.
"If the talks fail, the party will contest all the seats on its own," he said.
Yadav targeted both the Bharatiya Janata Party (BJP) and the alliance of Chief Minister Nitish Kumar's Janata Dal-United and the Rashtriya Janata Dal of Lalu Prasad.
"BJP is 'nagnath' and Nitish Kumar is 'girgit' (chameleon) as he changed his colours."
He accused Nitish Kumar of betraying Samajwadi Party chief Mulayam Singh Yadav by joining hands with the Congress.
In last Bihar assembly polls, the Samajwadi party contested 146 seats but didn't win any.