(a) Postal Service employees, except those mentioned in paragraph (b) of this section, are subject, at all times to restrictions on their participation in political activity (5 U.S.C. subchapter III of chapter 73, and 18 U.S.C. 602,603,and,and.

(b) Those Postal Service employees who are employed on an irregular or occasional basis; e.g., experts and consultants, substitute rural carriers, others on a per diem basis, and without compensation or when actually employed employees, are subject to the restrictions mentioned in paragraph (a) of this section only while in an active duty status and only for the entire 24 hours of any day of actual employment. Notwithstanding this paragraph, full-time employees in a leave status and part-time employees are fully subject to the restrictions of paragraph (a) of this section.