No employee shall be granted a leave of absence for the purpose of entering employment for another employer or becoming self-employed. If a leave of absence is falsely obtained and the employee is found to be employed by another employer or to be self-employed while on a leave, the employee shall be given the opportunity to resign from service with the City. If the employee fails or refuses to resign, then the employee may be discharged provided that the discharge will be subject to review under the grievance procedure provided herein.