Employees of the federal government by law are guaranteed the right to
refrain from assisting a union. See 5
U.S.C. § 7102 (federal employees generally); 39
U.S.C. § 1209(c) (postal employees). (U.S.C. stands for "United
States Code." To access the United States Code, click
here.) This means that you cannot be required to pay any dues or fees
to the union in violation of your religious beliefs.