A group of Kansas City residents hope to get an initiative on a local ballot requiring voter approval before any terminals at Kansas City International Airport can be torn down or replaced.

The group, called “Friends of KCI,” has begun gathering signatures of registered voters. Group spokesman John Murphy says 3,500 signatures are needed to get the initiative on a ballot.

Mayor Sly James has created a 24-member advisory group to study the current airport, and the local Chamber of Commerce has come out in favor of a $1.2 billion proposal to consolidate it into one terminal.

Critics of the current layout say it’s inefficient, while supporters say the design makes it easy to get to and from terminal gates.