Precisely estimating the membership of trade union confederations in Poland in the years 1918–1939 is difficult, but we can assume that there were from 0.8 to 1.4 million trade unionists. Although the number of members of trade union organizations was relatively small, they played an important role in Polish social and political life. The trade union movement in the Second Polish Republic reflected political and occupational splits within the labor force, as well as its regional differentiation during the time of the partition of Poland. Although the membership of main trade union confederations was dynamic, the most influential currents of the movement–class trade unions and national-solidaristic trade unions–remained unchanged.
