The SSTP consisted of radical leftists who split from the Social Democratic Party of Finland after the Finnish Civil War of 1918.
[1] On the second day of the founding congress, the SSTP decided to join the Communist International, after which the police dispersed the meeting and arrested the participants, some of whom were later sentenced to imprisonment.
SSTP's program was written by Otto Wille Kuusinen, member of the Central Committee of the SKP.
Finnish Workers' Central Election Committee was formed on February 24, 1922 by representatives of the SSTP, Finnish Trade Union Federation (SAJ), Social Democratic Youth League of Finland and Social Democratic Women's League of Finland.
In early 1923, the SSTP changed its name to Workers' Party of Finland (Suomen Työväenpuolue, STP), removing reference to socialism.