The filing of such petition shall be authorized only by ordinance of the governing body of the political subdivision adopted by the affirmative vote of not less than two-thirds of all the members elected to such governing body, except that in the case of a county or of a school district governed by the provisions of chapter 7 of the title Education (s. 18:7-1 et seq.), such filing shall be authorized by resolution of the governing body adopted by the affirmative vote of not less than two-thirds of all the members elected to such governing body. For the purposes of this article the board of education of a school district governed by the provisions of said chapter 7 shall be deemed to be the “governing body” of such school district.