Major opposition groups have been rocked by intensifying internal strife since the Upper House election, and with the secretaries-general of the Democratic Party of Japan, Your Party and Nippon Ishin no Kai (Japan Restoration Party) launching a nonpartisan policy study group next week, speculation is flying they might try to form a new party.

However, policy stances of the three key lawmakers — Goshi Hosono of the DPJ, Your Party's Kenji Eda and Yorihisa Matsuno of Nippon Ishin — still differ markedly, and whether they can gather a substantial number of lawmakers behind them is unclear.

Hosono is regarded as a center-left liberal, whereas Nippon Ishin's members have advocated right-leaning, significantly more nationalistic policies.