Before filing the complaint of July 2009, ALTER-EU had a dense correspondence with the European Commission asking for explanations about the lack of transparency around most of the expert groups by that time and their composition.
Bellow you can find all letter written by ALTER-EU and the Commission's responses.
MEP Erik Meijer also submitted written questions around this issue. Youn can find them here with the answers given by Mr Barroso:
This whole pressure contributed to the improvement of transparency on expert groups.