Inoue started preparing "Jichisei Kenkyu Kai" (a study group for autonomy) with Munemitsu MUTSU and Shuzo AOKI on October 15, 1888 after Inoue joined the cabinet, and it was virtually a committee for a new political party with a party newspaper called "Jichi Shinpo" (New Autonomy News).
井上の入閣後の同年10月5日、陸奥宗光・青木周蔵らとともに事実上の新党準備会にあたる「自治制研究会」を発足させて機関誌『自治新報』を発行するなど準備を進めた。