Lalu Prasad Yadav made the appeal to Paswan after his efforts to reach him went in vain.
He said LJP's anguish over numbers of seats being offered to it by RJD and Congress was not a "big deal" as talks among them were still on.
"He is a nice man, decent man. I don't know who is misleading him. I want to appeal to him through you that he should not join communal forces (BJP) which will destroy this country," Lalu Prasad Yadav told reporters.
The former Bihar chief minister, Lalu Prasad Yadav, whose party is fighting for survival after suffering electoral reverses in previous elections, said he was hopeful of an alliance with him. "LJP and RJD should work together to save the nation," he said.
He played down LJP's concerns that its talks with RJD and Congress were heading nowhere.
Lalu Prasad Yadav said he had made every effort to contact Lalu Prasad Yadav after reading reports on the possible LJP-BJP alliance but failed.
"I just called up his home. His PS says he does does not know where Ram Vilas Paswan is. What kind of PA he is who does not know the whereabouts of his boss" he asked.