Massachusetts Gov. Charlie Baker on Friday vetoed a plan that would have let the state issue driver’s licenses to illegal immigrants over identity verification concerns as well as concerns involving voting.

The bill (H4805), if passed, would have seen illegal immigrants issued a standard driver’s license from the state if they applied starting July 1, 2023. People who apply would need to provide some proof of identity, date of birth, and state residency.

A spokeswoman for Massachusetts House Speaker Ron Mariano said the chamber plans to take an override vote on June 8, according to the State House News Service. A two-thirds vote is needed in each chamber to enact the legislation.

In a letter to the state legislature (pdf), the Republican governor said he could not sign the measure, saying the state’s motor vehicle registry does not have the ability to verify the identities of illegal immigrants.

“The Registry does not have the expertise to verify the validity of many types of documents from other countries,” he wrote in his veto message.

“This legislation also undoes a critical safeguard to the driver’s license issuance process that I signed into law just six years ago,” he added. “Consequently, a standard Massachusetts driver’s license will no longer confirm that a person is who they say they are.”

He also said the measure would “significantly increase the risk that noncitizens will be registered to vote.”

This is because the bill does not have any measures that would help tell apart a lawful citizen and an illegal immigrant, and furthermore, it restricts the registry from sharing citizenship information with “entities responsible for ensuring that only citizens register for and vote in our elections,” he said.

Baker previously told reporters on May 9 that, if the bill passes, there would be “huge numbers of provisional votes, which will then make it harder for people to figure out who actually won elections.” The state has two elections upcoming, with primaries on Sept. 6 and the general election on Nov. 8.

Massachusetts’ Secretary of the Commonwealth disagreed. He told the Boston Globe on the same day, “How the governor manages to link that to the license issue, I am confused and baffled.”

“I do think that the governor in his comments and the Republicans in general in their comments on this issue have tried to raise the specter that this will allow these persons to vote,” he said at the time. “Nothing could be further from the truth … he is making this rhetorical assertion that there are going to be people voting, which they are not.”

Supporters of the bill say it could help improve safety on roads.

Elizabeth Sweet, executive director of the Massachusetts Immigrant and Refugee Advocacy (MIRA) Coalition said that she was “deeply disappointed” in Baker’s veto of the measure.

“The policy would not only make our communities safer, but benefit our economy and bolster trust between law enforcement and immigrant communities,” she said in a statement, reported WBUR. “We hope that the legislature will waste no time in overriding the Governor’s veto.”

The bill had passed the state House and Senate—both with Democrat majorities—with more than enough votes to override any veto from the governor. The House initially passed the bill with a 120-36 vote, and the Senate voted in favor with a 32-8 vote. On May 26, the House voted 118-36 to accept the conference committee report on the measure.

If the measure becomes law, Massachusetts would join 16 states and the District of Columbia in allowing illegal immigrants to be issued driver’s licenses.