(a) Assignment for deduction of dues
If the Department has received from any individual a written assignment which authorizes the Department to deduct from the salary of that individual amounts for the payment of regular and periodic dues of the exclusive representative, the Department shall honor the assignment. Any such assignment shall be made at no cost to the exclusive representative or the individual. Except as provided in subsection (b), any such assignment may not be revoked for a period of one year from its execution.

(b) Termination of assignment for deduction of dues
An assignment for deduction of dues shall terminate when—

(1) the labor organization ceases to be the exclusive representative;

(2) the individual ceases to receive a salary from the Department as a member of the Service; or

(3) the individual is suspended or expelled from membership in the exclusive representative.

(c) Negotiations with uncertified labor organizations
During any period when no labor organization is certified as the exclusive representative of employees in the Department, the Department shall have the duty to negotiate with a labor organization which has filed a petition under section 4111(b)(1)(A) of this title alleging that 10 percent of the employees in the Department have membership in the organization if the Board has determined that the petition is valid. Negotiations under this subsection shall be concerned solely with the deduction of dues of the labor organization from the salary of the individuals who are members of the labor organization and who make a voluntary allotment for that purpose. Any agreement between the Department and a labor organization under this subsection shall terminate upon the certification of an exclusive representative of any employees to whom the agreement applies.

(d) Official time usage
The following provisions shall apply to the use of official time:

(1) Any employee representing an exclusive representative in the negotiation of a collective bargaining agreement under this subchapter shall be authorized official time for such purposes, including attendance at impasse proceedings, during the time the employee otherwise would be in a duty status. The number of employees for whom official time is authorized under this paragraph shall not exceed the number of individuals designated as representing the Department for such purposes.

(2) Any activities performed by any employee relating to the internal business of the labor organization, including the solicitation of membership, elections of labor organization officials, and collection of dues, shall be performed during the time the employee is in a nonduty status.

(3) Except as provided in paragraph (1), the Board shall determine whether any employee participating for, or on behalf of, a labor organization in any phase of proceedings before the Board shall be authorized official time for such purpose during the time the employee would otherwise be in a duty status.

(4) Except as provided in paragraphs (1), (2), and (3), any employee representing an exclusive representative, or engaged in any other matter covered by this subchapter, shall be granted official time in any amount the Department and the exclusive representative agree to be reasonable, necessary, and in the public interest.