Already beset by opposition attacks, Prime Minister Naoto Kan is facing another threat to his leadership: a deepening rift within his Democratic Party of Japan over how to punish scandal-ridden party don Ichiro Ozawa.
Kan's bid to pass the fiscal 2011 budget and related bills is already in doubt as Liberal Democratic Party-led opposition forces, who control the Upper House, step up their attacks.
Nevertheless, the more daunting challenge for Kan is bringing Ozawa and his followers into the fold. Key bills that are destined to die in the Upper House need to be overridden by a two-thirds majority in the more powerful Lower House.