Arizona plans to implement a dual-track voting system allowing people who register to vote without submitting proof of citizenship to cast ballots only for federal offices — such as Congress— but not for state or local offices, officials said Monday.

Secretary of State Ken Bennett will administer the system recommended under an opinion issued Monday by Attorney General Tom Horne, Bennett spokesman Matt Roberts said.

“Because Arizona law requires a registration applicant to provide evidence of citizenship, registrants who have not provided sufficient evidence of citizenships should not be permitted to vote in state and local elections unless a dual registration system is invalid under the federal or state constitution,” Horne said in his opinion.

In 2014, the only federal offices on Arizona ballots will be U.S. House seats.

If the change announced Monday by Bennett and Horne sticks, it would mean voters who haven’t submitted proof of citizenship could not vote for such offices as governor, secretary of state, attorney general and state House or Senate. Those voters also wouldn’t be able to vote on ballot measures.

On their ballots, “they would just be getting the offices that they’re eligible to cast their ballots for,” Roberts said.

However, Roberts acknowledged that a legal challenge is likely. “We’ll see how this shakes out, but elections officials don’t get to wait and see. We’ll be implementing.”

The vast majority of Arizonans register to vote by using a state form that requires proof of citizenship, which is required under a 2004-voter approved law. That proof can include an Arizona driver’s license issued after 1996, a U.S. birth certificate, a passport or another similar document.

However, the U.S. Supreme Court ruled in June that Arizona and other states are required to accept a federal voter registration form.

The federal form requires registrants to say they’re citizens, but it doesn’t require that they submit proof such as documents.

While the Supreme Court said Arizona must allow people to use the federal form, the justices also said Arizona could ask the federal Election Assistance Commission to approve the citizenship proof requirement. Then, if the commission refused, Arizona could ask a federal court to overturn the commission’s decision.

Arizona and Kansas in August filed a federal lawsuit in an attempt to force the federal commission to change its voter registration forms to compel proof of citizenship.