Four opposition parties jointly called on the Cabinet Thursday to immediately convene an extraordinary Diet session to reopen deliberations on the Kake Gakuen scandal, invoking Article 53 of the Constitution.

Article 53 obliges the Cabinet to open another Diet session following the annual ordinary session that closed June 18.

According to procedures outlined in the article, the Cabinet must convene an extraordinary Diet session "when a quarter or more of the total members of either House makes the demand."