According to the replies of the Spanish Cortes Generales to the questionnaire for the 13th Bi-annual Report of COSAC (May 2010):
"2. ENSURING COMPLIANCE WITH THE PRINCIPLE OF SUBSIDIARITY
2a. Please specify the Parliamentary bodies in charge of ensuring such compliance.
The proceedings relating to the compliance with the principle of subsidiarity is entrusted to the Joint EU Committee. According to the draft Resolution, the Bureau of the Joint Committee, together with the Spokespersons, will be entrusted with the preliminary scrutiny of all EU legislative proposals. The plenaries of any of the two Chambers of the Cortes Generales may also be involved if they so decide.
2b. Briefly describe the procedures involved.
According to the draft resolution, the legislative proposals will be submitted to a preliminary scrutiny of the Bureau, together with the Spokespersons, of the Joint Committee. The Bureau may then refer the proposal to the Joint Committee and appoint a subcommittee to draft a reasoned opinion. Two Parliamentary Groups or a fifth of the members of the Joint Committee may also initiate the proceedings by tabling a draft reasoned opinion to the Joint Committee. The procedure must be initiated within the first five weeks after the reception of the draft legislative act.
Once the draft reasoned opinion, alternative drafts and amendments have been tabled, the Chair will convene the Joint Committee to debate and put the draft to a vote.
If the plenaries of any of the Chambers decide to recall the final vote, the reasoned opinion of the Joint Committee will be debated and put to a vote in both Plenaries.
2c. Briefly describe the procedures for the participation of regional parliaments, if applicable.
As soon as the Joint Committee receives a draft EU legislative act, the Committee will refer it to all Regional Parliaments through email. Any Regional Parliament may then table a reasoned opinion to the Joint Committee within a four-week period. The reasoned opinions of the Regional Parliaments will not be binding to the Cortes Generales, but if the Joint Committee approves a reasoned opinion on the same draft act, the list of opinions of the Regional Parliaments will be attached to the Cortes’ opinion, together with the relevant references to facilitate their consultation."