D.C. Code § 4-205.19l

(a) The Mayor shall not require a TANF recipient to participate in a work activity that:
(1) Results in the displacement of any currently-employed worker or position, including partial displacement, such as a reduction in hours of nonovertime work, wages, or employment benefits;
(2) Impairs existing contracts for services or collective bargaining agreements;
(3) Results in the employment or assignment of the TANF recipient, or the filling of a position with the TANF recipient when any other person is on layoff from the same or a substantially equivalent job within the same organizational unit, or when an employer has terminated any regular employee or otherwise reduced its workforce with the intent of filling the vacancy so created by hiring the TANF recipient; or
(4) Results in the TANF recipient participating in community service, work experience, or subsidized employment when such participation is the equivalent of filling an established unfilled position vacancy, or is the equivalent of performing a job that is substantially similar to the vacant position, unless the TANF recipient is given a bona fide opportunity to apply for the position as an unsubsidized employee after 18 weeks of satisfactory service in the position.
(b) The Mayor shall establish and maintain a grievance procedure for resolving complaints by any person, organization, or bargaining unit that claims to have been adversely affected by a violation of this subsection.
(c) Nothing in this section shall be construed to prevent a collective bargaining agreement from containing additional protections for a regular employee.