Prime Minister Yoshihiko Noda needs to give assurances that he will dissolve the Lower House and call a snap election before the Liberal Democratic Party votes for his social security and tax reform bills in the Upper House, the leader of the top opposition party said Monday.

"It's about time" for Noda's administration to ask for a public judgment via a general election, LDP President Sadakazu Tanigaki told reporters in Hiroshima Prefecture.

LDP Secretary General Nobuteru Ishihara also said the prime minister must state when the Lower House will be dissolved if he wants to break the deadlock over his key bills.