DES MOINES, Iowa–Republican presidential candidate Sen. Ted Cruz (R-TX) is remaining defiant amid criticism regarding his controversial mailer, saying that he will “apologize to nobody.”

The Cruz campaign sent a flyer out to Iowa voters, that resembled a government document, which read “VOTING VIOLATION.” The flier included names, grades, and percentage scores for each voter.

“Your individual voting history as well as your neighbors’ are public record,” reads the flier sent to voters. “Their scores are published below, and many of them will see your score as well. CAUCUS ON MONDAY TO IMPROVE YOUR SCORE and please encourage your neighbors to caucus as well. A follow-up notice may be issued following Monday’s caucuses.”

Cruz, however, is not apologizing for the mailer.

“I will apologize to nobody for using every tool we can to encourage Iowa voters to come out and vote,” Cruz told reporters in Iowa.

Matt Schultz, the Cruz campaign’s Iowa state chairman, also defended the fliers.

“These mailers are common practice to increase voter turnout,” Schultz said in a statement. “Our mailer was modeled after the very successful 2014 mailers that the Republican Party of Iowa distributed to motivate Republican voters to vote, and which helped elect numerous Republican candidates during that cycle.”

Iowa’s secretary of state, Paul Pate, blasted Cruz for the flier.

“Today I was shown a piece of literature from the Cruz for President campaign that misrepresents the role of my office, and worse, misrepresents Iowa election law,” Paul Pate said in a statement.

“Accusing citizens of Iowa of a ‘voting violation’ based on Iowa caucus participation, or lack thereof, is false representation of an official act,” Pate said. “There is no such thing as an election violation related to frequency of voting. Any insinuation or statement to the contrary is wrong and I believe it is not in keeping in the spirit of the Iowa caucuses.”

Republican presidential candidate Sen. Marco Rubio (R-FL) also blasted Cruz for the mailer, telling reporters in Iowa that voters had approached him about it.

“They were upset about it, obviously. They had people’s names and they gave them an ‘F’ rating for how they voted. I think a lot of voters are disturbed by it,” he said. He added that it’s “an unusual way to end your campaign in the state.”

The idea for the controversial mailer reportedly came from a study conducted by political scientists who wanted to find out whether peer pressure increases voter turnout.

According to The Washington Post: