((a)) Whoever, otherwise than as provided by law for the proper discharge of official duties, directly or indirectly—
((1)) demands, seeks, receives, accepts, or agrees to receive or accept any compensation for any representational services, as agent or attorney or otherwise, rendered or to be rendered either personally or by another—
((A)) at a time when such person is a Member of Congress, Member of Congress Elect, Delegate, Delegate Elect, Resident Commissioner, or Resident Commissioner Elect; or
((B)) at a time when such person is an officer or employee or Federal judge of the United States in the executive, legislative, or judicial branch of the Government, or in any agency of the United States,
((2)) knowingly gives, promises, or offers any compensation for any such representational services rendered or to be rendered at a time when the person to whom the compensation is given, promised, or offered, is or was such a Member, Member Elect, Delegate, Delegate Elect, Commissioner, Commissioner Elect, Federal judge, officer, or employee;
((b)) Whoever, otherwise than as provided by law for the proper discharge of official duties, directly or indirectly—
((1)) demands, seeks, receives, accepts, or agrees to receive or accept any compensation for any representational services, as agent or attorney or otherwise, rendered or to be rendered either personally or by another, at a time when such person is an officer or employee of the District of Columbia, in relation to any proceeding, application, request for a ruling or other determination, contract, claim, controversy, charge, accusation, arrest, or other particular matter in which the District of Columbia is a party or has a direct and substantial interest, before any department, agency, court, officer, or commission; or
((2)) knowingly gives, promises, or offers any compensation for any such representational services rendered or to be rendered at a time when the person to whom the compensation is given, promised, or offered, is or was an officer or employee of the District of Columbia;
((c)) A special Government employee shall be subject to subsections (a) and (b) only in relation to a particular matter involving a specific party or parties—
((1)) in which such employee has at any time participated personally and substantially as a Government employee or as a special Government employee through decision, approval, disapproval, recommendation, the rendering of advice, investigation or otherwise; or
((2)) which is pending in the department or agency of the Government in which such employee is serving except that paragraph (2) of this subsection shall not apply in the case of a special Government employee who has served in such department or agency no more than sixty days during the immediately preceding period of three hundred and sixty-five consecutive days.
((d)) Nothing in this section prevents an officer or employee, including a special Government employee, from acting, with or without compensation, as agent or attorney for or otherwise representing his parents, spouse, child, or any person for whom, or for any estate for which, he is serving as guardian, executor, administrator, trustee, or other personal fiduciary except—
((1)) in those matters in which he has participated personally and substantially as a Government employee or as a special Government employee through decision, approval, disapproval, recommendation, the rendering of advice, investigation, or otherwise; or
((2)) in those matters that are the subject of his official responsibility,
((e)) Nothing in this section prevents a special Government employee from acting as agent or attorney for another person in the performance of work under a grant by, or a contract with or for the benefit of, the United States if the head of the department or agency concerned with the grant or contract certifies in writing that the national interest so requires and publishes such certification in the Federal Register.
((f)) Nothing in this section prevents an individual from giving testimony under oath or from making statements required to be made under penalty of perjury.