The Justice Department has put the brakes on enactment of a proposed election-law overhaul signed by South Carolina’s Republican Gov. Nikki Haley, saying it wants more evidence that the changes will comply with Section 5 of the Voting Rights Act.

The department requested additional information from the state’s election commission about the law, which requires voters to present photo ID at the polls—a sign that the department has reservations about the changes. South Carolina is one of nine states that must receive preclearance for any changes made to election law.