5 CFR §734.306

1. (a)An employee may not participate in political activities subject to the provisions of subpart E of this part:
   1. (1)While he or she is on duty;
   2. (2)While he or she is wearing a uniform, badge, insignia, or other similar item that identifies the employing agency or instrumentality or the position of the employee;
   3. (3)While he or she is in any room or building occupied in the discharge of official duties by an individual employed or holding office in the Government of the United States or any agency or instrumentality thereof; or
   4. (4)While using a Government-owned or leased vehicle or while using a privately-owned vehicle in the discharge of official duties.
2. (b)The prohibitions in paragraph (a) of this section do not apply to employees covered under subpart E of this part.