The certification by the Clerk of the sufficiency of a referendary petition within thirty (30) days after the passage of the ordinance to which such petition refers shall automatically suspend the operation of the ordinance adopted by the electorate through initiatory proceedings may not be amended or repealed by the Council for a period of two (2) years after the date of the election at which it was adopted. 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.