The principle of legitimate expectation (legitimate trust) arises from the societal need to provide security for established legal statuses; such statuses already extant must not be jeopardized. Individuals have a right to legitimate trust in law based on applicable legal rules or judicial guarantees. A person should not be faced with or surprised by unexpected legal rules or new administrative decisions. The core aim of legitimate expectation is to secure the legal system from any formal and substantive legislative differences or shortcomings embedded in the texts. A legal authority, constitutional or administrative, must exist that is prepared to define the legal text and apply it in the disputes submitted for judgment. The administrative judiciary decides on the legality of those decisions issued against individuals through a formal action (i.e. court case) filed by the individual as plaintiff. In many countries, the key means the administrative judiciary uses to protect the rights of individuals are: the principle of legality, the appeal to misuse, and res judicata. These and the principle of the hierarchy of legal rules as a guarantee of legitimate expectation are discussed at length.
The paper examines three categories of legal guarantees regarding individuals’ legitimate expectations: (a) constitutional jurisdiction, (b) administrative jurisdiction and (c) the role played by the legislative and executive authorities in such protection. As examples, empirical representative cases adjudicated in UAE, Egyptian and Iraqi law are discussed in detail.