The labor movement followed a policy of collaboration with the middle classes in order to build the nation and protected the private sector in the Yishuv. After the founding of Mapai, the labor movement became an acceptable party for the capitalists in the World Zionist Organisation, and especially for the left wing of the General Zionists. This cleared the way for the labor movements domination of the WZO in the late 1930s and 1940s. The internal democracy of the labor movement was very poor. Only about ten percent of the Histadrut members were also party members. The Histadrut bureaucracy manned the Mapai party institutions as well, together with kibbutz members. In this situation there were no really independent supervisory institutions. The middle level of the Histadrut had to supervise its superiors and the higher level had to supervise itself. For their political future the functionaries were mainly dependent on each other, and not on the rank and file of the movement. According to Sternhell, "as long as the leadership was able to close ranks, there was no means of ejecting people from their positions". Freedom of expression was normal, and ideological dissent was allowed, but as soon as either threatened the system the nonconformist was eliminated without mercy. Usually even threatening with this was not necessary though. Mapai had no need to function as a voluntary body. The leaders derived their authority from their control of the Histadrut, which provided essential services for three out of four Jewish employees in Palestine. Elections were not held, as proscribed, every two years, but from the mid-1920s on rather less frequent. For instance, the Histadrut conventions were held in 1921, 1923, 1927, 1933 and 1942. Elections for other counsels were held similarly infrequent. Executive bodies were set up by appointment committees and were sanctioned by bodies whose members were either workers in the Histadrut or one of its enterprises, or representatives of the collective settlements. Due to the indirect election system, the higher up in the organisation, the less accountable a representative was. Thanks to this system the leadership enjoyed a wide freedom of action. There was a demand for democracy though. This focussed on more frequent and regular elections and direct election of individual party functionaries. Many people were conscious that Mapai and the Histadrut were only outwardly democratic. For instance, when the Histadrut executive was expanded with 12 members in 1937 Ben-Gurion announced to Mapai's Central Committee: "The committee proposes adding 12 members, and they are [a list follows].