 The 6th Congress was attended by 3,062 delegates with voting rights and 158 without them; this marked an increase of 1,349 voting and 137 non-voting delegates from the 5th Congress. The increase indicates a growth in membership. The 6th Congress is significant for its large number of delegations: 177 delegations from 118 countries were represented. While communist and workers' parties customarily invite "fraternal parties" to party congresses, the WPK had taken the unusual step of not inviting foreign delegations to the 1st, 2nd and 5th congresses. Among those invited this time were the Communist Party of China and the Communist Party of the Soviet Union. The WPK leadership also invited a number of non-communist parties and organizations to the congress. The official report said that 155 foreign organizations from 105 countries attended the congress, indicating that 22 delegations remained incognito. For unknown reasons, no foreign delegates spoke at the congress.
