Yadav will be the Leader of the Opposition in state assembly as BJP is now the main opposition after Janata Dal-United snapped ties with it.
He was the road and highways minister in the JD-U-BJP government led by Nitish Kumar.
The JD-U walked out of the NDA on June 16 on the issue of appointment of Narendra Modi as head of BJP election campaign committee.
Sushil Modi will be the chief of the BJP Vidhan Mandal (comprising of all party legislators from both the Houses).
BJP sources said members of the parliamentary board, party's highest decision-making body, were consulted on phone by the central leadership on this issue and their consent taken.
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