Upon filing of such report by the Planning Commission or upon the expiration of said 35 days as aforesaid and after notice has been given as provided in § 213-79A hereof, the City Council shall hold a public hearing and hear and consider said matter, at which time the statement of the vote of the Planning Commission approving, disapproving or proposing modification of such proposal shall be publicly read or, in the alternative, a public statement made by the Planning Commission, as filed, to report on the proposal. Where a proposed amendment is by petition, within 65 days following the conclusion of said hearing the City Council, acting as the Zoning Commission, shall act on the petition. If the Planning Commission reports negatively, the City Council, acting as the Zoning Commission, would require a 2/3 vote to approve a zone change.