The boundaries of Willoughby Hills shall continue as presently constituted unless or until changed in the manner provided by law, provided that
a - territory detached from, or annexed to such boundaries; or
b - merger of Willoughby Hills with any other body politic; or
c - termination of its existence as a municipal corporation;
may only be accompanied by action of Council in a manner subject to review by a vote of the electors upon referendum petition, or by vote of a majority of the electors of Willoughby Hills at a general, primary or special election, pursuant to an initiative petition.