New Jersey Assembly Republicans are calling for a bipartisan legislative investigation into the state’s automatic voter registration system after Governor Mikie Sherrill disclosed on Tuesday that thousands of non-U.S. citizens were mistakenly registered to vote through the Motor Vehicle Commission.

In a letter sent today to Assembly Speaker Craig Coughlin, all 23 Republican members of the Assembly urged the creation of a Special Legislative Committee on Election Integrity with subpoena power to investigate the errors, which state officials say resulted in approximately 6,600 non-U.S. citizens being improperly registered to vote.

In a press conference on Tuesday, Sherrill revealed that the Motor Vehicle Commission’s voter registration system had incorrectly registered thousands of non-citizens, including about 400 who subsequently cast ballots. Sherrill said she directed her chief counsel to investigate the matter, ordered the improperly registered voters removed from the rolls and said the state would replace the vendor responsible for the system.

Assembly Republicans argued that an executive branch investigation alone is insufficient.

“Every New Jersey citizen who cast a lawful ballot deserves confidence that the state’s voter registration system is accurate and secure,” the lawmakers wrote. They said public confidence could only be restored through “a transparent, independent investigation conducted in public, with witnesses testifying under oath.”

The lawmakers proposed a bipartisan committee with equal numbers of Republican and Democratic members and co-chairs appointed by the majority and minority leadership.

They also requested that the committee compel testimony from former acting Motor Vehicle Commission Chief Administrator Trish Littles-Floyd, representatives of the commission’s technology vendor, Idemia, former Secretary of State Tahesha Way and current Secretary of State Dale Caldwell.

Republicans also cited a recent letter from U.S. Homeland Security Secretary Markwayne Mullin to Caldwell that they said identified 35,152 non-citizens registered to vote in New Jersey — a figure they noted is significantly higher than the 6,600 registrations disclosed by the state.

“That discrepancy alone warrants legislative scrutiny,” the lawmakers wrote, adding that New Jersey residents deserve an explanation for the difference between the two figures.

The lawmakers said public hearings should examine when state officials first learned of the registration errors, why the issue was not disclosed sooner, whether reforms were delayed and whether additional problems remain within the automatic voter registration system.

The letter asks Coughlin to establish the committee “without delay.”

Neither Coughlin’s office nor the governor’s office has announced whether they would support the proposal.