At the time, an attempt was made by opposition parties to the social-liberal administrative coalition headed by German Chancellor Willy Brandt to block the ratification of the Basic Treaty of 1972. The treaty was negotiated by Brandt's administration to establish good neighborly relations with the German Democratic Republic, while preserving the premise of the reunification clause. This attempt, however, was thwarted by a ruling of the German Supreme Court, which cited the autonomous powers that are constitutionally vested in the political parties regarding how the reunification clause was to be implemented.