Center-right, one-issue environmentalist party founded and led by former Cabildo Abierto deputy and constitutional law professor, Eduardo Lust. Party was launched to lead opposition to the UPM 2 (UPM Paso de los Toros) project, which is the largest cellulose pulp plant in Uruguay, situated on the banks of the Rio Negro near the Rincón de Baygorria dam [Partido Constitucional Ambientalista (PCA)].