The council is the "upper house" of the European Parliament, representing the member states. While council votes are public, many decisions are made in negotiations long before a vote, the EUobserver reported Thursday.
The legal fight began this year when Access Info, a Spanish freedom of information group, sought access to documents on proposed amendments that would have limited access to information. The group got the documents with the names of countries backing the amendments concealed and asked the EU General Court to order the list be made public.
A "clear majority" of member states now backs an appeal to the European Court of Justice, EUobserver said it has learned.
"The decision-making process as established, the 'space to think' must be protected. This is what is at stake," a source said.