I.K. Dashkovsky was a member of the Social-Democratic movement in
Russia, became a member of the Bolshevik Party in 1917, member of the democratic centralism group in the years 1920-1921. Member of the Joint Opposition 1926-1927 years [source; https://www.eunet.lv/library/win/TROCKIJ/Arhiv_Trotskogo__t1.txt ] There are two articles from Dashkovsky online, which were written somewhere in 1928 [ https://www.eunet.lv/library/win/TROCKIJ/Arhiv_Trotskogo__t2.txt ] called 'The economic conjecture and the "Left" course' and 'On self-criticism'.
In 1956 Dashkovsky was rehabilitated and he started a struggle to bring the historical truth to light. In 1971 he even wrote a letter to the 24th party congress about this.