The court shall, upon a proper showing, issue a temporary restraining order or injunction under subsection (a) of this section without bond. Such injunction or order shall remain in effect until a complaint pursuant to section
2149 of this title is issued and dismissed by the Secretary or until an order to cease and desist made thereon by the Secretary has become final and effective or is set aside on appellate review. Attorneys of the Department of Agriculture may, with the approval of the Attorney General, appear in the United States district court representing the Secretary in any action brought under this section.