Left-wing Cypriot nationalist party founded by Vasos Lyssaridis. Party began as the "United Democratic Union of the Center" until merging with two smaller parties to form the Movement of Social Democrats (MSS) in 2000. Party then merged with the Citizens Alliance on June 24, 2021 to form the Movement of Social Democrats - EDEK. Party has been chaired by Marinos Sizopoulos since March 1, 2015 [Movement of Social Democrats – E.D.E.K. (K.S. E.D.E.K.); Κίνημα Σοσιαλδημοκρατών–Ε.Δ.Ε.Κ. (Κ.Σ. Ε.Δ.Ε.Κ.)].
