[Political parties]

(1) Political parties shall participate in the formation of the political will of the people. They may be freely established. Their internal organization must conform to democratic principles. They must publicly account for their assets and for the sources and use of their funds.
(2) Parties that, by reason of their aims or the behavior of their adherents, seek to undermine or abolish the free democratic basic order or to endanger the existence of the Federal Republic of Germany shall be unconstitutional. The Federal Constitutional Court shall rule on the question of unconstitutionality.
(3) Details shall be regulated by federal laws.