[3] The main task of the Federal Constitutional Court is judicial review, and it may declare legislation unconstitutional, thus rendering them ineffective.

Constitutional amendments or changes passed by the parliament are subject to its judicial review since they have to be compatible with the most basic principles of the Grundgesetz defined by the eternity clause.

[note 1] The Basic Law of the Federal Republic of Germany stipulates that all three branches of the state (the legislature, executive, and judiciary) are bound directly by the constitution in Article 20, Section 3 of the document.

The members of each senate are allocated to three chambers for hearings in constitutional complaint and single regulation control cases.

Specifically, it can vet the democratic and constitutional legitimacy of bills proposed by federal or state government, scrutinise decisions (such as those relating to taxation) by the administration, arbitrate disputes over the implementation of law between states and the federal government and (most controversially) ban non-democratic political parties.

[10] The Constitutional Court enjoys more public trust than the federal or state parliaments, which possibly derives from the German enthusiasm for the rule of law.

[11] The court's judges are elected by the Bundestag (the German parliament) and the Bundesrat (a legislative body that represents the sixteen state governments on the federal level).

[12] This new procedure was applied for the first time in September 2017, when Josef Christ was elected to the first senate as the successor of Wilhelm Schluckebier.

If a vacancy is not filled within two months, the court may nominate a replacement itself at the request of the highest-ranking official of the responsible body – either the oldest member of the Richterwahlausschuss or the president of the Bundesrat.

[13] This amendment also added a provision allowing regular law to provide for the transfer of one legislative body's right to elect a judge to the other.

In practice, this measure removes the veto power over judge nominations of a so-called "blocking minority" (Sperrminorität) in the Bundestag – an uncooperative party which is in opposition but has over one-third of seats.

The president of the Federal Constitutional Court ranks fifth in the German order of precedence, as the highest-ranking representative of the judicial branch of government.

One complaint is the perceived function as a replacement lawmaker (German: Ersatzgesetzgeber) because it has overturned controversial policies numerous times, such as the Luftsicherheitsgesetz,[19] the Mietendeckel [de] (rent cap) of Berlin,[20] and parts of the Ostpolitik.

[22] He considers that to hinder the efficiency of German intelligence agencies in favour of protecting people in far-away countries.

[34] In this regard, the ruling of 5 May 2020 deemed an act of the EU and the Weiss Judgment of the Court of Justice "ultra vires", for having exceeded the powers granted by the Member States.