2 U.S.C. § 288c: Defending the Senate, committee, subcommittee, member, officer, or employee of Senate

defend the Senate, a committee, subcommittee, Member, officer, or employee of the Senate in any civil action pending in any court of the United States or of a State or political subdivision thereof, in which the Senate, such committee, subcommittee, Member, officer, or employee is made a party defendant and in which there is placed in issue the validity of any proceeding of, or action, including issuance of any subpena or order, taken by the Senate, or such committee, subcommittee, Member, officer, or employee in its or his official or representative capacity; or defend the Senate or a committee, subcommittee, Member, officer, or employee of the Senate in any proceeding with respect to any subpena or order directed to the Senate or such committee, subcommittee, Member, officer, or employee in its or his official or representative capacity. Representation of a Member, officer, or employee under subsection (a) shall be undertaken by the Counsel only upon the consent of such Member, officer, or employee.