A federal judge in Aberdeen says he’ll rule by Jan. 2 on a state law that will require ballot petition circulators to register and be included in a directory.

The organization SD Voice seeks an injunction to stop the law from taking effect next July. It requires petition circulators to apply with the secretary of state for an identification number, provide personal information and be included in a directory.

SD Voice says the law is unconstitutional.

Attorneys for the state said this week the law is aimed at preventing fraud.

Judge Charles Kornmann plans to issue a decision by Jan. 2.