WASHINGTON (Reuters) — Lawyers for the U.S. Justice Department on Monday filed a stinging rebuke to U.S. Senator Robert Menendez’s bid to have political corruption charges against him dismissed.

Menendez, a New Jersey Democrat and former chairman of the Senate Foreign Relations Committee, was indicted in April for bribery, accused of accepting up to $1 million worth of lavish gifts from Salomon Melgen, a Florida ophthalmologist, in exchange for political favors.

The two men, who are close friends, pleaded not guilty in April to the charges. Menendez was released without bail and Melgen was released on $1.5 million bond.

In pretrial motions both men sought to have the case against them dismissed and alleged misconduct in the investigation by U.S. prosecutors.

This was given short shrift by U.S. prosecutors in their own 65-page filing.

“The defendants’ motions are replete with so many factual inaccuracies and material misrepresentations that it is difficult to dismiss them as simply inadvertent,” lawyers for the U.S. government wrote.

They added: “Perhaps most troubling, the defendants accuse the government of concealing evidence from the grand jury, while themselves concealing from the court evidence material to their allegations.”

Abbe David Lowell, a lawyer for Menendez, declined to comment on the government’s court filing. Lawyers for Melgen did not immediately respond to a request for comment.

(Reporting by Lindsay Dunsmuir; Editing by Steve Orlofsky)

Senator Robert Menendez (D-NJ), a member of the Senate Foreign Relations Committee, makes remarks during hearings on “Corruption, Global Magnitsky and Modern Slavery – A Review of Human Rights Around the World”, on Capitol Hill in Washington, July 16, 2015. REUTERS/Mike Theiler