The following answer has been given by the Council of the European Union on the request to publicise an EU document regarding the ACTA negotations (page 3, para 8; own highlight):
[T]he Council would like to point out that, since the entry into force of the Lisbon Treaty, the scope of the institutions' legislative activities is defined in primary law. Article 289(3) TFEU provides that "[l]egal acts adopted by legislative procedure shall constitute legislative acts". Yet, a procedure leading to the conclusion of an international agreement, as provided under Title V of the TFUE, does not constitute a legislative procedure within the meaning of Article 289 TFEU.On the ground of this assessment, the Council is refusing the full disclosure of the document requested.
I suppose that this assessment will also infringe the European Parliament's right to control the member states when they enter into international negotiations - so will MEPs accept this legal interpretation by the Council?