The Socialist Democratic Federation was a splinter party of the
Japan Socialist Party (JSP). Its emergence followed a series of upheavals involving this left-wing, opposition political party, which began with the establishment of the
Democratic Socialist Party in January 1960 and the later reemergence of the
Japan Communist Party (JCP). The exodus of its membership is partly attributed to the perceived pro-Communist tendencies on the part of the JSP leadership during the political crisis involving the revision of
Japan's Mutual Security Treaty with the United States. Experts also blame a diminished public support for the socialist party, particularly in big cities. The Socialist Democratic Federation became part of the non-liberal coalition that elected
Morihiro Hosokawa as Japan's Prime Minister in 1993. During this election, the Shaminren obtained 0.7 percent share of the vote, securing four seats in the Japanese
House of Representatives.
Socialist Citizen Federation (SCF) In 1977,
Hideo Den, Yutaka Hara and Yanosuke Narazaki defected from the SDP and formed the Shakai Club party. In 1993,
Satsuki Eda was head of the Science and Technology Agency in
Morihiro Hosokawa's
cabinet. . ==Presidents of the SDF==