The ECJ has held that national courts are not bound by precedents established by superior courts in circumstances where those precedents are incompatible with EU Law.
Almost four decades ago, in Rheinmülen-Düsseldorf, the ECJ ruled that national procedures could not prevent lower courts from making further preliminary references to the ECJ.
In Elchinov the ECJ has gone much further. The Bulgarian Supreme Court had overturned a decision of a lower court and remitted the case back for rehearing. The lower court, however, found itself unable to reach a decision compatible both with EU Law and the binding ruling of the superior national court. The ECJ held that the lower court must depart from national court procedure and precedent to ensure compatibility with EU Law.