In the end of 1901 the union adopted a programme which defined its mission as fighting for political freedom of the proletariat, and for socialism.
[1] In 1902, a Chita committee was formed, and groups in Achinsk, Barnaul, Kansk, Novonikolayevsk, Petropavlovsk and other locations.
In January 1903 the union was affiliated to the Russian Social Democratic Labour Party, and changed name to Siberian Social-Democratic Union - RSDLP Committee.
The 1st conference of the union held in the summer 1903 reaffirm the commitment of the organization to the Iskra line.
However, the delegates of the union at the 2nd RSDLP congress, Trotsky and V. E. Mandelson, took a Menshevik position.