Rare big button from the Union Of Communists Netherlands (VCN), later called the Party of Communists. The Union of Communists was a the result of a plit of the Communist Party Netherlands (CPN) because they removed Marxism-Leninism and democratic centralism from the party principles, prompted the VCN members to leave the party and start their own communist party. On November 2 and 3, 1985, the VCN, Party of Communists in the Netherlands was founded.
The button is from before they left the CPN and was made for the 1st. Congress of the VCN.