Federal authorities are demanding that Florida halt its ongoing push to remove thousands of voters from the rolls.
The U.S. Department of Justice on Thursday sent a letter contending the state's efforts to identify ineligible voters violates federal voting laws.
Federal officials say procedures the state is using to identify non-U.S. citizens have not been reviewed. Florida must get approval for changes in voting procedures because five counties are still covered by the Voting Rights Act of 1965.
The letter also says that removing voters from the rolls less than 90 days before a federal election also violates federal law.
A spokesman for the Florida Department of State said officials were reviewing the letter, but added the state is "firmly committed" to preventing ineligible voters from casting ballots.