((a)) At the option of each district court, jurors may be summoned and qualified in a single procedure, if the court’s jury selection plan so authorizes, in lieu of the two separate procedures otherwise provided for by this chapter. Courts shall ensure that a one-step summoning and qualification procedure conducted under this section does not violate the policies and objectives set forth in sections 1861 and 1862 of this title.

((b)) Jury selection conducted under this section shall be subject to challenge under for substantial failure to comply with the provisions of this title in selecting the jury. However, no challenge under shall lie solely on the basis that a jury was selected in accordance with a one-step summoning and qualification procedure authorized by this section.