When, during Yamagata's second term as cabinet head, Kanetake OURA, Eitaro KOMATSUBARA, and Banichiro YASUHIRO, bureaucrats who were all protegees of Yamagata, were appointed to the House of Peers by imperial selection and thereafter joined the Tea Party, the influence of the Tea Party began to grow, and they managed to acquire members from among the large-scale taxpayers and the barons, and during Hirata's tenure as Lord Keeper of the Privy Seal, from the late Meiji period into the early Taisho period, the group possessed 67 members at its largest; the Tea Party supported Taro KATSURA during the Keien period (1905-1912), and its power and influence grew to rival the Kenkyukai's.
第2次山縣内閣期に山縣系官僚出身で平田との結びつきが強かった大浦兼武・小松原英太郎・安広伴一郎が勅撰議員に任命されて茶話会に加入すると、勢力が拡大する方向に向かい、多額納税議員や男爵議員からも加入者を得て、平田が内大臣に立った明治末期から大正初期にかけて最大で67名の議員を擁して桂園時代においては桂太郎を支え、研究会と勢力を競うまでに成長した。