[17] Shas was founded in 1984, prior to the elections to the eleventh Knesset in the same year, in protest against the small representation of Sephardim in the largely Ashkenazi Agudat Yisrael,[13] through the merger of regional lists which were compiled in 1983.

In founding the party, Yosef received strategic help and guidance from Rabbi Elazar Shach, leader of Israel's non-Hasidic Haredi Ashkenazi Jews.

[18] Yosef founded the party in 1984 on the platform of a return to religion and as a counter to an establishment dominated by Ashkenazi Jews of European extraction.

Shas has at times been able to exert disproportionate influence by gaining control of the balance of power in the Knesset within the context of the traditionally narrow margin between Israel's large parties.

[citation needed] Following the 2009 elections, in which Shas won eleven seats, it joined Benjamin Netanyahu's coalition government and held four cabinet posts.

Yair Lapid of the Yesh Atid party and Naftali Bennett of The Jewish Home, who had won more seats and joined the coalition, both favored conscription of the previously exempt Haredi men into Israel's national service and a reduction in state financial support for Haredi families, policies Shas opposes.

[24] They were also accused of creating a straw party with the symbols of Otzma Yehudit, which was running on a joint list with Yachad during the election.

[28] In the same year, a tape was leaked of the party's former spiritual leader, criticizing Jerusalem Chief Rabbi Shlomo Amar.

[29] On 17 April 2020, a senior Likud minister, speaking on anonymity, told Al-Monitor that Deri was mediating the political coalition talks between Netanyahu and Blue and White leader Benny Gantz.

It was also reported that Deri "might even be open to a new alliance with Blue and White – now that its anti-clerical component, Yair Lapid, quit the party and went his own way" and would only commit to remaining with Netanyahu's coalition until the next election.

[9] At first, Shas followed a moderate policy on the Israeli–Palestinian conflict, after Yosef had declared that lives were more important than territories,[13] but by the 2010s it had moved to the right, opposing any freeze in Israeli settlement activity in the West Bank.

[17] In addition, it was skeptical towards the U.S. Obama Administration's intentions regarding the Israeli–Palestinian peace process and began to support a consolidation of Israeli settlement interests, especially regarding yeshivas and Jewish holy sites in the West Bank.

[32] One of Shas's demands is a compensation package for Sephardi and Mizrahi Jews who were forced to flee their home countries and leave their property behind.

[citation needed] Shas opposes any form of public expression of homosexuality, including Gay Pride parades, especially in Jerusalem.

In addition, MK Shlomo Benizri was convicted of bribery, conspiring to commit a crime and obstruction of justice on 1 April 2008.