No public utility franchise which is not revocable at the will of the city shall be granted unless the same shall have received the affirmative vote of three-fifths of the electors of the city voting thereon at a regular or special municipal election. No franchise shall be submitted under the provisions of this charter, to the electors at a special election, unless the cost of holding the election, as determined by the council, shall be paid to the treasurer in advance of calling said election by the grantee in such franchise.