He supported the Bolshevik faction at the 2nd Congress of the Russian Social Democratic Labour Party in 1903 .
Plekhanov soon rejected the idea of democratic centralism , and became one of Lenin and Trotsky 's principal antagonists in the 1905 St. Petersburg Soviet .
Although he supported the Bolshevik faction at the 2nd Congress of the Russian Social Democratic Labour Party in 1903 , Plekhanov soon rejected the idea of democratic centralism , and became one of Lenin and Trotsky 's principal antagonists in the 1905 St. Petersburg Soviet .