Also, a strong opposition from daimyos and hatamotos to Agechi-rei (confiscation command of territory) was arisen when Tadakuni tried to force it through in September 1843, and treachery by his trusted retainer, Yozo TORII, was revealed, who switched sides and gave classified documents to Toshitsura DOI, anti-Agechi-rei roju, both of which caused the dismissal of Tadakuni from roju on leap September 13 and the ultimate downfall of Tadakuni later.
また、天保14年（1843年）9月に上知令を断行しようとして大名・旗本の反対に遭うなどした上、腹心の鳥居耀蔵が上知令反対派の老中・土井利位に寝返って機密文書を渡すなどしたため、閏9月13日に老中を罷免されて失脚した。