The nation's second-largest opposition party may be on the verge of vanishing as rebellious members, who hold the party's official stamp and bankbook, threaten procedures to legally disband Ishin no To (Japan Innovation Party).

Osaka-based Ishin members, led by Osaka Mayor Toru Hashimoto, have recently been ousted from the party. They are now preparing the launch of a new national party called Osaka Ishin no Kai on Oct. 31.

The Osaka group argues that their expulsion is invalid, and are preparing to hold what they call a party convention on Saturday, at which they intend to disband Ishin no To.