Preliminary reference procedure
The preliminary reference procedure is used when a national court or tribunal refers a question of EU law to the European Court of Justice (ECJ) for a preliminary ruling so as to enable the national court, on receiving that ruling, to decide the case before it. Questions of EU law will arise in cases before the courts of different Member States. The function of the preliminary reference procedure is to ensure uniform interpretation and validity of EU law across all the Member States.
The procedure is laid down in Article 267 TFEU: ‘Where such a question is raised before any court or tribunal of a Member State, that court may, if it considers that a decision on the question is necessary to enable it to give judgment, require the Court of Justice to give a ruling thereon.’
While lower courts have discretion as to whether to make references to the ECJ, Article 267 TFEU excludes such discretion in the case of final courts of appeal.
The ECJ characterises the preliminary reference procedure as based on cooperation between national courts and the ECJ. However, it is the ECJ that controls this cooperation and sets its terms. In its ‘dialogue’ with national courts, it has the upper hand and has succeeded in co-opting national courts into an EU judicial system.
In practice, labour courts in the Member States have differed greatly in the use made of the preliminary reference procedure. Despite the uniform requirements of Article 267 TFEU, the number of references made by national labour courts in different Member States varies considerably.
The ECJ has been sensitive to the charge of usurping the role of national courts in deciding cases. However, the technique adopted by the Court is problematic. The ECJ aims to lay down EU law principles, but leaves the application of these principles to national courts. The boundaries are often unclear. A principle may be defined in terms that leave little or no discretion to national courts; or the principle may be defined so vaguely as to provide the national court with little in the way of useful guidance. Cases involving EU law on employment and industrial relations provide illustrations. For example, the European Court has laid down the principle that indirect discrimination is justifiable on objective grounds, which must, however, comply with the general principle of proportionality – but both objective grounds and proportionality are to be left for national courts to decide (Bilka-Kaufhaus GmbH v. Karin Weber von Hartz, Case 170/84,  ECR 1607).
Despite these difficulties, the preliminary reference procedure has become the most frequently used channel of access to the ECJ.