With 46 of its candidates elected in the polls, the BJP stood at the third position in the state, while the Sena was relegated to the fourth position with 44 candidates.
"As per the rules, we have more number of MLAs after the ruling alliance. So it is obvious we will get the post of leader of opposition in the assembly," state BJP general secretary Vinod Tawade told PTI.
However, there has been no discussion on the issue in the party and between the allies so far, Tawade said.
The Sena is also facing an embarrassment with the defeat of its leader Ramdas Kadam, who was leader of the ppposition for the past five years. In BJP, Jalgaon MLA Eknath Khadse's name is being discussed for the position.
However, the Sena is not ready to let go of the post easily. It is seeking the support of four candidates of the Peasants and Workers Party, who won with its backing and a former Sena activist Vivek Pandit, who won Independent from Vasai in Thane district.
The BJP has convened its first meeting on Friday, which will be addressed by BJP general secretary Gopinath Munde, and state president Nitin Gadkari.
A Sena source said if the position is taken by the BJP, it will also claim the deputy speaker's post in the assembly, usually held by the opposition.
"The BJP has to give us the post either in the assembly or in council. In similar manner, the post for deputy speaker and deputy chairman (in council) will be decided," the source said.