A US federal judge has temporarily blocked an Ohio law that required residents to provide documentary proof of citizenship when registering to vote during a driver's licence application. Judge Solomon Oliver Jr granted the preliminary injunction on Tuesday, ruling that the law likely violates the National Voter Registration Act (NVRA), a federal statute requiring states to offer voter registration through driver's licence applications, because a signed attestation of citizenship is sufficient to establish eligibility without demanding additional documentation. The ruling is a setback for Ohio's Republican-controlled legislature, which amended the state's longstanding "motor-voter" law last year amid unsubstantiated claims of noncitizen voting; the state's secretary of state, Frank LaRose, said his office will appeal.