SUMMARY
Protection of legitimate expectations is a general principle of European Union law that has been developed through the case-law of the Court of Justice of the European Union. There are several unresolved issues that have been pointed out by the analysis of the said case-law. These are inter alia: When is the European Union legislator bound by legitimate expectations generated by a preceding piece of (changed) legislation, when does the preceding administrative practice generate legitimate expectations; the issue of the lack of legitimacy in case of speculative activities, the issue of differentiation between unlawful decisions and unlawful representations in generating legitimate expectations. Other issues concern the relation between the European Union law and the Member States’ legal autonomy concerning the possibilities for unlawful administrative acts to generate legitimate expectations and the expiration of the time-period prescribed by national law for revocation of unlawful administrative decisions beneficial for a party concerned. In the latter case, a Member State may not plead national administrative rules in order to justify its failure to comply with the principle of effectiveness of European Union law. The aim of this paper is to analyse these issues and determine whether the regulatory framework of the European Union can be improved in order to avoid potential problems in practice. The analysis is based on the case-law of the Court of Justice of the European Union and legal acts of the European Union along with Croatian and foreign literature on administrative, constitutional and European law. These issues illustrate the deficiencies of the current legal framework of the European Union with a number of applicable legal sources and ate the same time they emphasise the need for a codification of administrative procedure on the Union level. There have been several initiatives in this respect but with no real effect, even though there is a legal basis for such an endeavour prescribed by the Treaty on the Functioning of the European Union. Such a codification should prohibit unlawful administrative acts from generating legitimate expectations. This would also resolve the issue of different treatment of national administrative decisions that may not generate legitimate expectations. Furthermore, unclear and arbitrary interpretations should be avoided, as in the case of speculative activities the existence of which is not easy to determine. Finally, application of different criteria in different areas of law should be avoided if there is no basis therefor in the Treaties.