Administrative officials derive their authority or jurisdiction from a legal instrument or rule, and may only do what a law authorises them to so. This is known as the principle of legality, which requires that administrative authorities not only refrain from breaking the law, but that all their content comply with the Constitution and particularly the Bill of Rights. The sources of administrative law are, in order of importance,
The Constitution is the supreme law of the land. Any law or act which is inconsistent with it has no force or effect. The effect of this provision is that laws and administrative acts must comply with the Constitution. The Constitution is binding on the executive branch of government in every sphere of administration. The importance of the Constitution as a source of administrative law was best articulated in Pharmaceutical Manufacturers, where Chaskalson P held that the control of public power by the courts through judicial review is a constitutional matter. The common-law principles that had been applied to control powers prior to 1994 have now been subsumed under the Constitution. As a source of administrative law, the Constitution establishes a variety of agencies and administrative structures to control the exercise of public power.
Legislation includes
Section 125(2)(b) of the Constitution states that the Premier of a province exercises its executive authority, together with the other members of the Executive Council, by implementing all national legislation within the functional areas listed in Schedules 4 or 5 of the Constitution, except where the Constitution or an Act of Parliament provides otherwise.
Section 151 of the Constitution states that the executive and legislative authority of a municipality is vested in its municipal council. The municipality has the right to govern, on its own initiative, the local government affairs of its community, subject to national and provincial legislation, as provided for in the Constitution.
Subordinate legislative bodies, such as the President, when promulgating proclamations, and ministers, when issuing regulations, do not have original legislative competence and must act within the confines of the enabling legislation. In Minister of Health v New Clicks, Chaskalson stated that the making of delegated legislation by a member off the executive is an essential part of public administration, in that it gives effect to legislative policies. Further, it provides the detailed infrastructure whereby this can take place.