Democratic Party of Japan and Ishin no To (Japan Innovation Party) on Friday officially agreed to merge into a new party, forming an alliance they hope will grow with the addition of other opposition parties as they gear up for the crucial Upper House election this summer.

The merger is aimed at helping the struggling DPJ — the biggest opposition party — get back on its feet and put an end to what it calls the "heavy-handed" leadership of Prime Minister Shinzo Abe.

Presidents of the two parties also agreed to urge a hodgepodge of other minority parties, presumably including the Social Democratic Party as well as Seikatsu no To (The People's Life Party & Taro Yamamoto and Friends), and independent lawmakers to join so the new party can increase its chances against Abe's conservative Liberal Democratic Party.