Constitutional complaints serve to ensure that citizens can assert their fundamental rights vis-à-vis the state. Any person can lodge a constitutional complaint claiming that an act of public authority has violated one of their fundamental rights, or equivalent rights enshrined in Arts.20(4), 33, 38, 101, 103, 104 of the Basic Law (Art. 94(1) no. 4a of the Basic Law).
Acts of all three branches of government – the legislative, the executive and the judicial branch – can be challenged. The Federal Constitutional Court examines whether the challenged acts are based on laws that are compatible with the Constitution and whether the fundamental rights have been observed in the application of these laws.
In constitutional complaint proceedings, the Federal Constitutional Court can declare an act of public authority to be unconstitutional, it can declare a law void, or it can reverse an unconstitutional decision and remand the matter to a competent court. Any follow-up decisions must be taken by the ordinary courts; for example, the Federal Constitutional Court does not award damages or initiate criminal prosecution.