The Democratic Party of Japan officially decided Monday to expel ex-party chief Ichiro Ozawa and 36 other House of Representatives members who submitted resignation letters from the ruling party in protest against Prime Minister Yoshihiko Noda 's sales tax hike proposal, media said.

But the party leadership alleviated the punishment for former Prime Minister Yukio Hatoyama, who also voted against the bills but said would stay with the party. The alleviation was seen as a move to avoid further split within the DPJ, according to Kyodo news.

Ozawa and Hatoyama, who have both served as DPJ chief for different terms, met on Monday as they both try to stop Noda's tax hike plan.

Noda, however, has previously repeatedly vowed to stake his political career on passing the legislation during the current Diet session.