The Supreme Court on Monday rejected an appeal from ex-Rep. William Jefferson (D-La.) and will not revisit constitutional Speech or Debate Clause protections.

Attorneys for the former Louisiana lawmaker asserted in court documents that the Justice Department violated the Constitution’s Speech or Debate Clause when prosecutors provided a grand jury with evidence of Jefferson’s legislative activities in order to obtain an indictment in 2007.

But the Supreme Court’s refusal to hear the Louisianan’s appeal upholds a November 2008 decision by the U.S. Court of Appeals for the Fourth Circuit, which rejected Jefferson’s appeal, although it did not rule on whether Speech or Debate violations existed. Instead, the appellate court stated that it was “barred … from looking behind an indictment to assess whether the grand jury had considered privileged legislative materials.—

Jefferson is charged with 16 counts of violating federal law for allegedly offering and accepting hundreds of thousands of dollars in bribes to promote business ventures in West African nations. He is seeking the dismissal of the corruption charges.

He is scheduled to go on trial June 2 in the U.S. District Court for the Eastern District of Virginia.