In case of a written protest against any proposed amendments of the regulations or districts, signed and acknowledged by the owners of 20% of the frontage proposed to be altered, or by the owners of 20% of the frontage immediately adjoining or across an alley therefrom, or by the owners of 20% of the frontage directly opposite the frontage proposed to be altered, if filed with the Village Clerk, the amendment shall not be passed except by a favorable vote of at least two-thirds of the Village Board of Trustees then holding office.
(`92 Code, § 40-8-5)