Abstract
EU law exerts increasing influence on domestic regulations of civil proceedings in consumer cases. The implementation of the requirements arising from the EU principle of effectiveness constitutes a difficult task due to the fact that EU law does not comprehensively regulate the obligations of domestic courts to guarantee legal protection provided by substantive law to consumers. The first part of this paper is meant to clarify, basing on the existing CJEU case law, the scope of the court's obligation to gather ex officio evidence to establish whether the case on hand involves a consumer as a party to litigation. In the author's opinion, this obligation is of a more general nature than it would appear from the CJEU's judgment in case