PHOENIX — Arizona officials on Wednesday emphatically denied claims of a widespread disqualification of Republican votes marked with Sharpie pens, which Democrats say is a misinformation effort to undermine the lead by former vice president Joe Biden.

Since before the election, election officials have tried to tell voters that it was fine to use a Sharpie, which were provided at certain polling places, as long as it was black or blue ink, using educational resources, including a cartoon video. Experts called mishaps “rare.” But that hasn’t stopped some conservatives from amplifying claims in the contested state that the problem was rampant.

Dubbed “Sharpiegate,” Trump allies, including an Arizona congressman, have questioned whether ballots were not counted while a conservative group filed a lawsuit. At least 575 people complained Wednesday to the Arizona attorney general, prompting the office to write to the Maricopa County Elections Department for more information.

“Apparently the use of Sharpie pens in GOP precincts is causing ballots to be invalidated,” Matt Schlapp, who heads the American Conservative Union, wrote in a tweet that was later labeled as possibly misleading by Twitter. “Could be huge numbers of mostly Trump supporters.”

Rep. Paul A. Gosar (R-Ariz.) tweeted that he asked Arizona Attorney General Mark Brnovich to look into the Sharpie issue. Katie Conner, a spokeswoman for Brnovich, said the office questioned election officials because the number of concerned callers means the issue is worth looking into and should not be labeled as a conspiracy.

“It’s not fair to dismiss their concerns, just because other people are calling it a conspiracy theory,” Conner said.

The Public Interest Legal Foundation, a conservative group that previously opposed the pandemic-era expansion of mail ballots, filed a lawsuit in the state’s Superior Court on Wednesday, alleging that a voter was not able to vote again after the Sharpie she used bled through the paper and the scanner was unable to read her ballot. County election officials did not immediately respond to The Post’s questions about the claim.

Arizona Secretary of State Katie Hobbs and multiple county officials have said there is no merit to the Sharpie concerns. They had even encouraged voters to use felt tip pens for ballots, saying the ink dries fast and is easy for scanners to read. But the misinformation still swirled.

“Poll workers are not going to give voters pens that are going to invalidate their ballot,” Hobbs told KTAR News on Wednesday.

Ballots in Maricopa County were arranged so that if a Sharpie did bleed through the page, it wouldn’t cause an unreadable mark on the other side, Hobbs said. She also emphasized that the state had a clear-cut adjudication process for counting ballots that could not be read by tabulators.

Election Integrity Partnership, a coalition of research groups tasked with dispelling misinformation, said there was no evidence that voters were disenfranchised by polling station workers who gave out Sharpies, contrary to social media posts that claimed votes were invalidated.

“In many states, sharpies can be used without issue, depending on the type of tabulation system used,” the group wrote on Twitter. “In rare cases, there may be concerns of ink bleeding through. These concerns can be addressed by hand counting ballots per state voter intent laws.”

With more than 400,000 ballots still uncounted, the winner has not been declared in the state, though Biden is in the lead. Fox News and the Associated Press have already called the state for Biden, but other news media have not.

One group that tweeted about the Sharpie issue, Students for Trump, is now planning a “Protect the Vote” rally at the Maricopa County ballot-processing center on Friday. Students for Trump Chairman Charlie Kirk said in a statement that the event is being held because hundreds of thousands of ballots in Arizona remain “outstanding.”

A spokesman for the group did not respond to further questions.

Maricopa County Elections Department spokeswoman Megan Gilbertson said “all the right people are aware” of the event. Local law enforcement said they do not discuss “safety plans” publicly.

Democrats have argued that the new claim by conservatives is an attempt to cast public doubt on the outcome in Arizona as Trump is behind in electoral votes. Officials have told voters that they can use Sharpie “from day one,” Steven Slugocki, chairman of the Maricopa County Democratic Party, said in an interview.

“They’re grasping for anything right now,” Slugocki said of Republicans, “and apparently they’ve decided to go with, ‘I used a Sharpie.’ ”

Teddy Amenabar contributed to this report.