A two-year dispute over California’s Department of Motor Vehicles voter registration procedures has again landed the agency in court.

On Tuesday, a coalition of voting rights groups filed a federal lawsuit alleging DMV officials still require drivers renewing their registration by mail to fill out a separate card if they also want to register to vote. That separate step, the lawsuit said, violates the 1993 “Motor Voter” law passed by Congress.

“It’s an embarrassment that in 2017, more than 20 years after the law was enacted, California DMV is still violating the law by making millions of people jump through hoops to become voters,” said Kathay Feng, executive director of California Common Cause.

The activist groups that filed the lawsuit, including the League of Women Voters of California and the National Council of La Raza, first threatened to sue the DMV in 2015 over its procedures that didn’t integrate voter registration into in-person and online driver’s license registration.

While new voter registration procedures were rolled out last spring, the groups said Tuesday that the DMV has refused to similarly combine the two processes for those who register by mail. The lawsuit said the state has failed “to provide eligible voters with the integrated application process required by law.”

The organizations represented by the lawsuit argued that lack of state action in registering more voters means their own advocates have been having to step in to fill the gap.

The debate comes as California is already expanding the connection between obtaining a license and registering to vote. In 2015, Gov. Jerry Brown signed a law that will register all eligible drivers license holders as voters unless they choose to “opt out.” The law was on hold until state elections officials completed testing of a statewide voter database. That process ended last year, and the automated process for registering voters is expected to be used before next year’s elections.

Jessica Gonzalez, a DMV spokeswoman, said the state has complied with the federal law for years.

“Today’s lawsuit serves as an unfortunate distraction from ongoing joint efforts by the secretary of state’s office and the DMV to further improve the voter registration process in California, which already exceeds the voter registration obligations set forth in the National Voter Registration Act,” Gonzalez said in a statement.

Secretary of State Padilla said in a statement that he “will continue working diligently with stakeholders and the DMV to expand voter registration opportunities.”

Update 4:50 p.m. The story was updated with a comment from Padilla.