CHICAGO (AP) — The Illinois Supreme Court has ruled a voter referendum seeking to change the system Illinois uses to draw political boundaries is unconstitutional, meaning it can’t appear on the November ballot.

The ruling Thursday affirms a Cook County judge’s decision that the proposal doesn’t meet constitutional muster. A county judge rejected a similar signature-driven effort in 2014.

The Independent Maps coalition, a group of bipartisan business leaders and former elected officials, gathered petitions calling for an 11-member commission to be in charge of drawing legislative district lines. Currently, the party in power runs political mapmaking.

The legal challenge was brought by an attorney linked to top Democrats. It was filed on behalf of minority business and community leaders who claimed the proposed system would diminish minority representation.