The split occurred at the 20th congress of EKP in March 1990, as a reaction against the decision of the congress to separate EKP from the Communist Party of the Soviet Union and rebrand itself into the Estonian Democratic Labour Party (EDTP).
Immediately after the independence decision of EKP, the pro-Soviet delegates left the congress venue.
[3][4] The party was often perceived, along with Intermovement, as representing the resistance of the Russian population in Estonia against independence.
A study on the electoral patterns of the 1990 Estonian Supreme Soviet election showed that the EKP (NLKP platvormil) candidates had a support of 13.3% of the non-Estonian voters.
Following the defeat of the coup, the party was declared illegal by the Estonian government on August 22, 1991.