"Nitish Kumar's opposition to Narendra Modi and communal forces was just a charade with an aim to corner Muslim votes," Prasad told reporters reacting on strain in ties between JD(U) and BJP.
RJD Chief Lalu Prasad Yadav.
"Why did not he resign from NDA after Gujarat riot in 2002 like Ramvilas Paswan did?" Prasad asked.
"Why did not he ordered a probe into Sabarmati train burning incident as a Railway minister in NDA government of Atal Bihari Vajpayee?" he said, adding, wasn't it done to help Narendra Modi.
He asked Kumar to tell the people "why did he hosted RSS Chief Mohan Bhagwat at CM's official residence, 1 Anne Marg?".
Poking fun at possibility of formation of a federal front, the RJD chief said "it is very difficult to rely on people like Nitish Kumar and Mamata Banerjee."
He said JD(U) is nothing but "a group of opportunists headed by Nitish Kumar and Sharad Yadav."
The people of the state are watching the entire "Ram lila" between JD(U) and BJP and would teach a lesson to them in coming elections.
The RJD President said Maharajganj Lok Sabha bypoll has started "countdown for fall of Nitish Kumar government."