U.S. Attorney General Jeff Sessions has asked the remaining 46 chief federal prosecutors appointed by President Barack Obama who have not already resigned to do so “in order to ensure a uniform transition,” the Justice Department said on Friday.

“Until the new U.S. attorneys are confirmed, the dedicated career prosecutors in our U.S. attorney’s offices will continue the great work of the department in investigating, prosecuting, and deterring the most violent offenders,” it said in a statement.

It is routine for a new president to appoint his own U.S. attorneys, who are political appointees.

The Justice Department statement cast doubt over the future of Preet Bharara, the Obama appointee who currently serves as the Manhattan-based U.S. Attorney for the Southern District of New York, whose office handles some of the most critical business and criminal cases passing through the federal judicial system.