Kumar thanked RJD president Lalu Prasad and said BJP's game plan to destabilise the Jitan Ram Manjhi government was over now and victory of the two JD(U) candidates was certain.
He also thanked Congress and CPI for extending support to his party in the polls and appealed to the dissidents to return to JD(U).
"I thank Lalu Prasad and RJD for supporting us. I had appealed to him three days ago to support us and check BJP's game plan to destabilise Jitan Ram Manjhi government," Kumar told reporters.
JD(U) has nominated former diplomat Pawan Kumar Varma and veteran leader Ghulam Rasool Baliyawi as candidates for the two RS seats, which fell vacant due to resignations of Rajiv Pratap Rudy and Ram Kripal Yadav after they got elected to Lok Sabha.
On the other hand, dissident legislators of JD(U) have propped up industrialist Sabir Ali and real estate baron Anil Sharma as Independent candidates in the bye-election, posing a stiff challenge to the official candidates of their party.