DISCIPLINARY ACTIONS-DEMOTION. An employee may be demoted for cause. A written statement of the reasons for any such action shall be transmitted to the employee and a copy transmitted to the Personnel Department for inclusion in the employee’s personnel file. No demotion shall be made as a disciplinary action unless the employee to be demoted is eligible for employment in a lower class and shall not be made if any regular employee in a lower class will be laid off by reason of the action.