Three opposition parties agreed Sept. 18 to introduce a no-confidence resolution in the Diet against convicted bribe-taker Koko Sato, the chief of the Management and Coordination Agency.

The agreement effectively leaves Sato with no option but to voluntarily give up his Cabinet post, possibly by the end of the week. Even his political allies in the ruling Liberal Democratic Party faction to which he belongs called Sept. 18 for his voluntary resignation. Until Sept. 16, the besieged Sato had claimed innocence in connection with the 1970s Lockheed bribery scandal, Japan's largest political corruption scandal in postwar years.

Executives from the three opposition parties -- Shinshinto, the Democratic Party of Japan and Taiyo Party -- agreed to introduce a no-confidence resolution against Sato to an extraordinary Diet session scheduled to be held late this month. Sato was appointed to the post by Prime Minister Ryutaro Hashimoto, despite his bribery conviction, at the urging of former Prime Minister Yasuhiro Nakasone, who effectively controls the 66-member faction. "We also agreed to continue questioning the responsibility of the Hashimoto Cabinet for causing this problem even after Sato resigns," Takeo Nishioka, secretary general of Shinshinto, the largest opposition party, told a news briefing after the meeting.