At the second conference of the Zionist Railway Workers' Union, held in Jaffa March 6–7, 1920, MPS was the largest bloc with seven delegates.
In order to counter the MPS influence in the union, Ahdut HaAvoda and Hapoel Hatzair joined forces.
At the club, named after Ber Borochov, left-wing Poalei Zion publications like Avangard of Vienna and Jüdische-Sozialistische Monatschrift from New York City were available.
The main theoretician of the party, Yaakov Meiersohn, had left Palestine for Vienna and Soviet Russia.
The delegates represented approximately 300 party members, from local branches in Haifa, Jaffa, Jerusalem, Petach Tikva and amongst road construction workers in Tiberias and Alexandria.
The list was led by Gershon Admoni, Avraham Revutkzy, Yaakov Sikador, Haim Katz, Mordechai Haldi, Y. Shapira and 'L.
26 delegates participated, representing local branches in Jaffa, Haifa, Jerusalem, Rehovot, Zikhron Ya'akov, Petach Tikva, Yavne, Sarafend, Tzemah and Kineret, the party branch at the Labour Battalion 'Migdal', the Central Committee and the youth and women's wings of the party.
Also, the intention of the party of forming Jewish-Arab class unity became more difficult as communal tension heightened.
The party found itself politically isolated, as polarization between Zionist and Arabic national aspirations aggravated.
The right-wing Zionist leader Ze'ev Jabotinsky accused the party of 'unforgivable treachery' a few days after the riots.