Patna, Feb 13 (IANS): Bihar Chief Minister Jitan Ram Manjhi Friday said his predecessor and senior JD-U leader Nitish Kumar made a "mahagalti" (huge mistake) by nominating him chief minister last year and that he is not a "rubber stamp chief minister".

"Nitish Kumar has not committed a mistake, but a huge mistake (mahagalti) by nominating me as chief minister because I am not a rubber stamp chief minister," Manjhi said at a crowded press conference at his official residence 1 Anne Marg here.

Manjhi said that Nitish Kumar failed to understand him despite being in politics for three and half decades.

"It was wrong to treat me as puppet...," Manjhi said in a reply to Nitish Kumar, who admitted Thursday that Manjhi's betrayal was a setback to him, especially since He handpicked Manjhi.

Manjhi also accused Nitish Kumar of indulging in horse trading.

"I am a poor man, how can i will do horse trading, Nitish Kumar is doing horse trading," he said.

Manjhi said that he was confident of proving his majority on the floor of the state assembly Feb 20.

"I will get adequate support of legislators...," he said.

Manjhi made it clear that he will not resign till he fails to prove his majority.