The certification by the clerk of the sufficiency of a referendary petition shall automatically suspend the ordinance in question pending repeal by the council or final determination by the electors, as the case may be. An ordinance adopted by the electorate through initiatory proceedings, may not be amended or repealed by the council for a period of two (2) years, and then only by the affirmative vote of not less than five (5) councilmen. Should two (2) or more ordinances adopted at the same election have conflicting provisions, the one receiving the highest vote shall prevail as to those provisions.