It supported the policy of subjecting Arab citizens to martial law, which included confining them to the towns of their residence, and allowing them to exit only with a permit granted by the Israeli authorities.

[10] Due to its role in emerging victorious and independent from the 1948 Arab–Israeli War, the party won large support in Israel's first elections in 1949, receiving 36% of the vote (well ahead of second-placed Mapam's 15%) and winning 46 of the 120 seats.

A notable piece of legislation enacted during Mapai's first term in office was an educational law in 1949 which introduced compulsory schooling for all children between the ages of 5 and 14.

However, he shocked the nation by resigning on 6 December 1953 in order to settle in the small Negev kibbutz of Sde Boker, and was replaced by Moshe Sharett.

The inquiry into the Lavon Affair which brought down the government in 1961 probably contributed to the party's relatively poor performance in the elections in the same year, as it picked up only 35% of the vote and 42 seats.

Although Ben-Gurion formed a strong coalition with the National Religious Party, Ahdut HaAvoda, Agudat Yisrael Workers, Cooperation and Brotherhood and Progress and Development, two events during the fifth Knesset led to Mapai's reducing dominance.

Firstly, Ben-Gurion resigned as head of the party citing personal reasons, though in reality he was upset at a perceived lack of support from colleagues.