The Mayor and/or a councilmember shall be removed from office (a) upon conviction of a felony, or (b) having been declared mentally incompetent by the circuit court, or (c) by extended absenteeism, defined as missing 50% of the meetings of the Mayor and Council within a six-month period. Removal from office under section (c) of this article shall be effected only after an advertised public hearing and shall require the affirmative vote of three members of the Council. A vote of three (3) members of the Council is required to initiate the hearing for removal.