If a written protest against a proposed amendment shall be filed in the office of the Zoning Administrator within ten days after the conclusion of the public hearing by the City Council, which protest is duly signed by the owners of 20% or more either of the area of the lots included in such proposed change, or of those immediately adjacent on the sides and in the rear thereof extending 300 feet therefrom and of those directly opposite thereto extending 300 feet from the street frontage of such opposite lots, such amendment shall not become effective, except by the favorable vote of three-fourths of all the members of the City Council.
(2005 Code, § 11-906)