It is, however, desirable that a decision to make a reference for a preliminary ruling should be taken when the national proceedings have reached a stage at which the referring court or tribunal is
able to define the legal and factual context of the case, so that the Court of Justice has available to it all the information necessary to check, where appropriate, that European Union law applies to the main proceedings. In t
he interests of the proper administration of justice, it may also be desirable for the reference to be made only af
...[+++]ter both sides have been heard.