Despite a failure by his ruling coalition and its allies to maintain a critical two-thirds majority in the Upper House, Prime Minister Shinzo Abe said Monday he remains eager to revise the nation's postwar Constitution, pinning his hopes on the possibility of being able to form a broad consensus with opposition parties.

Sunday's Upper House election saw pro-revision forces, including the ruling Liberal Democratic Party, its junior partner Komeito and conservative opposition party Nippon Ishin no Kai, stop short of winning enough seats to preserve the two-thirds majority in the 245-seat chamber.

Without this supermajority in the Upper House, Abe will not be able to initiate a national referendum on revising the charter, which is often regarded by nationalists as a humiliating postwar imposition by the U.S.-led Occupation forces.