The opposition camp on Monday called for Prime Minister Yoshiro Mori's immediate resignation, while Mori himself continued to deny that he offered to step down when he proposed moving up the Liberal Democratic Party election.

"None of the top five executives of the party (present during a closed-door meeting Saturday with Mori) took (my proposal) as an announcement of my resignation," Mori told the Upper House Budget Committee. "I myself have not said such a thing, either."

Opposition lawmakers grilled Mori over what he meant when he proposed to top LDP officials Saturday that the next party presidential election be moved up. The election, which will effectively choose the next prime minister, was originally slated for September, when Mori's term as party chief expires.