JD(U) Legislative Council member Sanjay Singh filed the criminal defamation suit against the Rashtriya Janata Dal president in the court of Chief Judical Magistrate R K Yadav.
It was admitted and listed for hearing tomorrow.
Singh has alleged that Prasad had made a derogatory reference to him and and another former MLC Sanjay Jha at a 'Parivartan rally' here on May 15.
Singh, who had crossed over to Nitish Kumar's party from the LJP of Ramvilas Paswan, told PTI that Prasad was "using unparliamentary language against his opponents and lowering the dignity of politics out of frustration".