A judge blocked Wisconsin election officials Tuesday from using a federal voter registration form, finding they never formally approved its use.

Conservative law firm Wisconsin Institute for Law and Liberty filed a lawsuit in September 2022 asking a judge to declare the National Mail Voter Registration Application illegal in the state.

The lawsuit, filed on behalf of Waukesha resident Richard Braun, alleged that the form doesn't include places to fill in information such as whether a voter has been convicted of a felony and how long they've lived in their district. The lawsuit goes on to argue that the Wisconsin Elections Commission never authorized the form's use and never developed administrative rules governing its use.

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WEC attorneys argued that the form was approved by an election agency that preceded the commission.

Waukesha County Circuit Judge Michael Maxwell ruled that the WEC never authorized it and never promulgated any administrative rules governing its use. WEC attorneys couldn't produce any credible evidence on when, where or how the form was approved, he added.

With that settled, he said, there was no need to determine whether the form complies with Wisconsin law.

Gillian Drummond, a spokesperson for the state Justice Department, which defended the WEC in the lawsuit, didn't immediately respond to an email seeking comment on the ruling.

Federal law requires many states to use the form, which is provided by the U.S. Election Assistance Commission. Wisconsin isn't one of those states, however, because the state allows voters to register at the polls on Election Day.

Wisconsin residents don’t need to use the federal form to register to vote. In addition to same-day registration, they can can register online, at their municipal clerk’s office or by mail with a state form, which is available in English, Spanish and Hmong on the WEC website.