An initiative or referendum petition may be amended at any time within ten days after the notification of insufficiency has been sent by the City Clerk, by filing a supplementary petition upon additional papers and filed as provided in case of an original petition. The City Clerk shall, within five days after such an amendment is filed, make examination of the amended petition and, if the petition be still insufficient, he/she shall file his/her certificate to that effect in his/her office and notify the committee of petitioners of his/her findings and no further action shall be had on such insufficient petition. The finding of the insufficiency of a petition shall not prejudice the filing of a new petition for the same purpose.