Reasoned opinion

Any national Parliament or any chamber of a national Parliament may, within eight weeks from the date of transmission of a draft legislative act, in the official languages of the Union, send to the Presidents of the European Parliament i, the Council i and the Commission i a reasoned opinion.

This should state why it considers that the draft in question does not comply with the principle of subsidiarity. It will be for each national Parliament or each chamber of a national Parliament to consult, where appropriate, regional parliaments with legislative powers.