The US Department of Justice (DOJ) Tuesday filed a lawsuit against the state of Arizona over an election law that requires state residents to provide proof of citizenship in order to vote in presidential and other federal elections.

House Bill 2492 was signed by Arizona Governor Doug Ducey in March. The law obliges those voting in federal elections to provide a document such as a birth certificate, passport or naturalization certificate to prove that they are US citizens. It also requires proof of citizenship to be established before voters can receive a mail-in ballot.

The DOJ’s case to overturn the Arizona law rests on a 2013 Supreme Court decision, Arizona v. Inter Tribal Council, Inc. The court ruled the federal 1993 National Voter Registration Act preempted Arizona from requiring proof of citizenship when applicants register to vote with federal forms. The 2013 decision found that states could not impose additional restrictions or forms on those eligible to vote.

The DOJ is also challenging a separate provision of the law that allows state officials to deny applications based on errors irrelevant to voting requirements, saying that it violates Civil Rights Act of 1964.

In a statement, Assistant Attorney General Kristen Clarke of the Civil Rights Division said:

Arizona has passed a law that turns the clock back on progress by imposing unlawful and unnecessary requirements that would block eligible voters from the registration rolls for certain federal elections. The Justice Department will continue to use every available tool to protect all Americans’ right to vote and to ensure that their voices are heard.

Set to take effect January 2023, HB 2492 was passed after the state emerged as a key electoral winner for President Biden in the 2020 US Presidential election, a result which brought about widespread and unfounded claims of voter fraud.

A 2021 decision by the Supreme Court upheld another Arizona law restricting voting access that forbid out of precinct voting and vote tampering.