He served as head of the General Zionists and was a founding member of the Gahal party.

Between 1940 and 1951 he served as the mayor of Petah Tikva, where a major street (part of Road 481) is named after him.

[3] Sapir served as a Minister without Portfolio in Levi Eshkol's emergency government formed on the eve of the Six-Day War.

He assumed the post of Minister of Trade and Industry in Golda Meir's government, until Gahal left the coalition on 6 August 1970.

[2] Karmei Yosef, a community settlement founded in 1984 between Ramle and Beit Shemesh, is named in his honor.