Federal prosecutors pushed back on former Sheriff Joe Arpaio's bid to call Attorney General Jeff Sessions to testify at the Arizona lawman's upcoming criminal contempt trial.
Lawyers for the U.S. Department of Justice urged a judge in a court filing Monday to reject Arpaio's subpoena of Sessions.
Session runs the agency that is prosecuting the retired sheriff on a criminal contempt-of-court charge for defying a judge's 2011 order to stop his immigration patrols.
Prosecutors say Arpaio hasn't shown any extraordinary circumstances to call Sessions, the federal government's top lawyer, to testify on a matter on which he had no involvement or firsthand knowledge.
Arpaio's trial is scheduled to begin on Monday in federal court.
The former sheriff has acknowledged prolonging the patrols but insists his defiance wasn't intentional.