After the death of theorist Ber Borochov, the left-wing and centrist of Poalei Zion split in February 1919 with Ben-Gurion and his friend Berl Katznelson leading the centrist faction of the Labor Zionist movement.
The moderate Poalei Zion formed Ahdut HaAvoda with Ben-Gurion as leader in March 1919.

In 1920 he assisted in the formation of the Histadrut, the Zionist Labor Federation in Palestine, and served as its General Secretary from 1921 until 1935.
At Ahdut HaAvoda's 3rd Congress, held in 1924 at Ein Harod, Shlomo Kaplansky, a veteran leader from Poalei Zion, proposed that the party should support the British Mandatory authorities' plans for setting up an elected legislative council in Palestine.
He argued that a Parliament, even with an Arab majority, was the way forward.
Ben-Gurion, already emerging as the leader of the Yishuv, succeeded in getting Kaplansky's ideas rejected.

In 1930, Hapoel Hatzair (founded by A. D. Gordon in 1905) and Ahdut HaAvoda joined forces to create Mapai, the more moderate Zionist labor party (it was still a left-wing organization, but not as far-left as other factions) under Ben-Gurion's leadership.
In the 1940s the left-wing of Mapai broke away to form Mapam.
Labor Zionism became the dominant tendency in the World Zionist Organization and in 1935 Ben-Gurion became chairman of the executive committee of the Jewish Agency, a role he kept until the creation of the state of Israel in 1948.

During the 1936–1939 Arab revolt in Palestine, Ben-Gurion instigated a policy of restraint ("Havlagah") in which the Haganah and other Jewish groups did not retaliate for Arab attacks against Jewish civilians, concentrating only on self-defense.
In 1937, the Peel Commission recommended partitioning Palestine into Jewish and Arab areas and Ben-Gurion supported this policy.
This led to conflict with Ze'ev Jabotinsky who opposed partition and as a result Jabotinsky's supporters split with the Haganah and abandoned Havlagah.

The house where he lived from 1931 on, and for part of each year after 1953, is now a historic house museum in Tel Aviv, the "Ben-Gurion House".
In 1946, Ben-Gurion and North Vietnam's Politburo chairman Ho Chi Minh became very friendly when they stayed at the same hotel in Paris.
 Ho Chi Minh offered Ben-Gurion a Jewish home-in-exile in Vietnam.
Ben-Gurion declined, telling Ho Chi Minh: "I am certain we shall be able to establish a Jewish Government in Palestine."
After the death of theorist Ber Borochov, the left-wing and centrist of Poalei Zion split in February 1919 with Ben-Gurion and his friend Berl Katznelson leading the centrist faction of the Labor Zionist movement. The moderate Poalei Zion formed Ahdut HaAvoda with Ben-Gurion as leader in March 1919. 
In 1920 he assisted in the formation of the Histadrut, the Zionist Labor Federation in Palestine, and served as its General Secretary from 1921 until 1935. At Ahdut HaAvoda's 3rd Congress, held in 1924 at Ein Harod, Shlomo Kaplansky, a veteran leader from Poalei Zion, proposed that the party should support the British Mandatory authorities' plans for setting up an elected legislative council in Palestine. He argued that a Parliament, even with an Arab majority, was the way forward. Ben-Gurion, already emerging as the leader of the Yishuv, succeeded in getting Kaplansky's ideas rejected.
In 1930, Hapoel Hatzair (founded by A. D. Gordon in 1905) and Ahdut HaAvoda joined forces to create Mapai, the more moderate Zionist labor party (it was still a left-wing organization, but not as far-left as other factions) under Ben-Gurion's leadership. In the 1940s the left-wing of Mapai broke away to form Mapam. Labor Zionism became the dominant tendency in the World Zionist Organization and in 1935 Ben-Gurion became chairman of the executive committee of the Jewish Agency, a role he kept until the creation of the state of Israel in 1948.
During the 1936–1939 Arab revolt in Palestine, Ben-Gurion instigated a policy of restraint ("Havlagah") in which the Haganah and other Jewish groups did not retaliate for Arab attacks against Jewish civilians, concentrating only on self-defense. In 1937, the Peel Commission recommended partitioning Palestine into Jewish and Arab areas and Ben-Gurion supported this policy. This led to conflict with Ze'ev Jabotinsky who opposed partition and as a result Jabotinsky's supporters split with the Haganah and abandoned Havlagah.
The house where he lived from 1931 on, and for part of each year after 1953, is now a historic house museum in Tel Aviv, the "Ben-Gurion House". In 1946, Ben-Gurion and North Vietnam's Politburo chairman Ho Chi Minh became very friendly when they stayed at the same hotel in Paris.  Ho Chi Minh offered Ben-Gurion a Jewish home-in-exile in Vietnam. Ben-Gurion declined, telling Ho Chi Minh: "I am certain we shall be able to establish a Jewish Government in Palestine."
David Ben-Gurion