MONTGOMERY, Ala. — The names of Alabama voters who crossed party lines to vote in last month’s Republican Senate runoff will be given to prosecutors, the state’s election chief said Friday.

Secretary of State John Merrill said his office has identified 674 people who voted in the Democratic primary and later voted in the GOP runoff in violation of the state’s new crossover voting ban. Merrill said he plans to send the names to the attorney general and district attorneys after local election officials check the list for errors.

The move signals a hardline approach to the new state law — used for the first time in the U.S. Senate runoff — that adds fraudulent crossover voting to the list of other felony voting crimes, such as voting twice. Merrill said it was the “right thing” to report violations but noted that it is prosecutors’ decision on whether to pursue charges.

The move drew criticism from those who said voters could face prosecution for an honest mistake as the ban came into effect for the first time, but Merrill said it was his responsibility to report possible violations.

“It’s the law. We’re going to enforce the law. We’re not bullying anybody. We’re enforcing the law,” Merrill told The Associated Press.

Alabama Democratic Party Chairwoman Nancy Worley said the ban was new in this election and you “would automatically have more problems.”

“Going out on a witch hunt is the wrong word, but I think it is problematic that you would seek out people who crossed over and voted without assuring that every single training, every single instruction, every single understanding was followed in this election,” Worley said.

Alabama does not require primary voters to register with a political party. State lawmakers this spring approved the crossover ban in an attempt to prevent voters of one political party from trying to meddle in another party’s runoff — although there is a dispute about how much that actually happens. The law prohibits a person from voting in one party’s primary and then switching to the other’s runoff and makes violations a low-level felony punishable by more than one year in prison and a $15,000 fine.

The proposal was backed by members of the GOP, which dominates Alabama politics. Republicans hold all statewide offices.

The law was used for the first time in the Sept. 26 Republican runoff in the race to replace Attorney General Jeff Sessions in the U.S. Senate. The potential 674 crossover votes did not affect the outcome of that race because Republican Roy Moore defeated Sen. Luther Strange by more than 44,000 votes.

Merrill said he was concerned that some poll workers were not enforcing the law. He said poll workers should face prosecution as well if they were found to have aided voters.

The secretary of state’s office sent probate judges a spreadsheet of the names identified. Incidents ranged from as few as one voter per county to 380 in Jefferson County, the state’s most populous area. Merrill’s office asked elections officials to check the names and report any errors by Nov. 6.

“Unless our Office receives notification from your county that certain voters should not be on this listing of crossover voters, we will submit the list as-is to the proper authority to begin investigation and possible prosecution,” the memo stated.

Asked if prosecutions would be pursued for crossover voting, a spokeswoman for Alabama Attorney General Steve Marshall said she could not immediately say.

“The general policy of the Attorney General’s Office is not to comment about whether a particular matter may or may not be investigated,” Marshall’s press office responded by email.