立憲政友会
In 1924, he was elected as an independent candidate in the Japanese general election of 1924 to the lower house of the Diet of Japan, but joined the "Rikken Seiyūkai" party the following year. He was reelected in 1928, 1930, and in 1932. In 1934, contrary to the orders of the "Rikken Seiyūkai" party he joined the cabinet of Prime Minister Okada as Minister of Agriculture and Forestry and was promptly expelled from the party. In response, Yamazaki formed the small "Shōwakai" political party, together with Tokonami Takejirō in 1935, and was reelected again in the 1936 General Election.