In 1960, when Suehiro Nishio formed the Democratic Socialist Party, some Diet members who belonged to the Kawakami faction of the JSP defected to the DSP. In so doing, it is said that Chairman Kaoru Ōta of the General Council of Trade Unions of Japan requested Kawakami not to move the entirety of his own faction over to the DSP in exchange for election cooperation. However, in order to restrain the feelings of the Kawakami faction, Kawakami himself ran for the JSP leadership election, and lost to the Suzuki faction-endorsed candidate Inejiro Asanuma by a narrow margin. The Kawakami faction was pleased with this unexpected show of support and thus its agitation in favour of the DSP subsided, and as a result Kawakami succeeded in keeping even the slightest factionalism in the JSP at bay. However, following Inejirō Asanuma's death later in October 1960, after a brief period in which Saburō Eda was acting chairman, Kawakami was elected to be the JSP's chairman.