This dataset includes partition identifiers obtained from retweet networks collected before the 2019 Finnish Parliamentary Elections and before the 2023 Finnish Parliamentary Elections from conversation streams related to Finnish political parties (SDP, National Coalition, Finns Party, Green Party, Left Party, Center Party) and salient topics (economic policy, social security, immigration, climate, education). The column headers in the two files are the same and indicate the topic of the retweet network. Each row in one file represents all the memberships of one particular Twitter account for the corresponding networks. Memberships are obtained by partitioning each retweet network with METIS algorithm into two similar-sized groups with minimal retweet activity between them. For each column, one partition includes all users marked with 0, whereas the other partition includes all users marked with 1. The order of the numbering is random. Missing values mean that the account was not found in the corresponding network. The dataset does not contain any identifying information or original raw data from the Twitter platform. Anonymization was achieved by randomly shuffling the order of the users so that, within each file, a row index identifies a user. Importantly, there no correspondence can be implied between users in 2019 and users in 2023: in general, the user at row 1 in the 2019 dataset is not the same as the user at row 1 in the 2023 dataset.