An Upper House member who quit the Liberal Democratic Party last week to help found a new party to challenge Prime Minister Junichiro Koizumi's administration switched to another new party Wednesday in a campaign ploy for the Sept. 11 Lower House election.

Kensei Hasegawa, who just a week ago took part in the founding of Kokumin Shinto (People's New Party) with three other LDP rebels and a defector from the Democratic Party of Japan, has joined New Party Nippon, said Nagano Gov. Yasuo Tanaka, the head of the party.

Adding Hasegawa allows New Party Nippon, founded Sunday, to field the same candidates in both single-seat constituencies and proportional-representation blocs for the election. New Party Nippon had been one parliamentarian short of qualifying as a legally registered party.