In this joint letter, 18 members of the European Parliament, Nuclear Transparency Watch and CEE Bankwatch Network are asking the European Commission, as an opinion-making party of relevant international conventions, to provide leadership and express its clear support for the findings of relevant committees during the upcoming Meetings of Parties of Espoo Convention in June and of the Aarhus Convention in September, in favour of a coherent application of the Espoo and Aarhus Conventions to nuclear lifetime extensions.