This article is devoted to the evolution of the environmental agenda of the European Union and its influence on the transformation of the main European political parties, as well as the reflection of these changes in the course and results of the European election campaign in 2019. According to the EU’s leadership ambitions in protecting the environment and combating climate change, and the high level of concern among the citizens of its member states, this agenda remains one of the most important ones. Despite the differentiation of theirideological features, a comparative analysis of the evolution of the courses of main European parties has shown that Euro-optimist parties strive to adapt existing environmental tasks to their main political priorities and/or to multiply current European achievements. At the same time, Eurosceptic parties mostly either do not deny or even ignore the environmental issues, trying to criticize the mechanisms already used by the European Union. As a result, the author reveals the connection of public support for environmental measures with the transformation of the rhetoric of European parties as well as the increase of both the ‘green’ members of the European Parliament and representatives of a set of other parties which paid more attention to environmental issues. In addition, the reasons for voters’ preference in a group of member states for Eurosceptic parties with predominantly non-environmental priorities were explained.