Democratic Party of Japan President Ichiro Ozawa offered his resignation Sunday as head of the biggest opposition force over the rift caused by his controversial handling of a proposal for a grand coalition with the ruling bloc.

Ozawa drew heavy criticism within his party for not immediately turning down the proposal Friday by Prime Minister Yasuo Fukuda to form a new coalition government.

The fact that Ozawa took the matter back to the DPJ for further discussion among party executives — who rejected the proposal — was taken as proof that he was interested in teaming up with the LDP, drawing fire from other opposition parties as well as numerous DPJ lawmakers.