The congressional race for an open seat in Georgia has gotten heated and personal between two Republicans with the frontrunner, Marjorie Taylor Greene, hiring a high-profile lawyer to demand her opponent, John Cowan, take down a "false and defamatory" ad that accuses her of failing to screen out illegal immigrants at her construction business.

But Cowan refuses to remove the campaign ad and says the cease and desist letter filed by Greene's attorney proves his claims on immigration are true. Greene countered with a new ad that says it's really Cowan who doesn't use E-Verify to vet employees.

Both are running as pro-Trump, pro-gun, pro-law enforcement conservative Republicans. The immigration dust-up in Georgia's 14th congressional district happened after Cowan, a neurosurgeon, unveiled a blistering ad on social media on July 8 that says Greene "refused to use E-verify" at her business, Taylor Commercial, and therefore she's aiding the flow of "illegal aliens" crossing the Mexican border to take American jobs.

Marjorie Greene

E-Verify is a Department of Homeland Security web-based program that allows enrolled employers to confirm the legal immigration status of employees and their eligibility to work in the United States. Georgia passed a law in 2011 to require employers to use E-Verify, with companies the size of Taylor Commercial needing to implement the tool starting July 1, 2013.

But Greene says Taylor Commercial has been using E-Verify consistently since 2010 -- three years before the company was legally required to do so in 2013 under Georgia's E-Verify law.

FACEBOOK PULLS AD FROM GUN-TOTING GEORGIA CANDIDATE TAKING ON ANTIFA: 'BIG TECH CENSORSHIP OF CONSERVATIVES MUST END'

"No one likes a liar," Greene said, pointing out that a quick search shows the company's long E-Verify history. "John Cowan is a huge liar."

Greene hired lawyer L. Lin Wood, who sent Cowan a sharply worded letter Wednesday threatening legal action if he doesn't retract the ad and apologize. Wood has represented Richard Jewell, the security guard falsely accused in Atlanta Olympics bombing in 1996, and Covington Catholic High School student Nicholas Sandmann, who sued the Washington Post for defamation last year.

"The false accusations made by you on behalf of your campaign to discredit your political opponent unlawfully exceed the permissible parameters of political speech and makes you, and your campaign, liable for monetary damages for defamation," Wood wrote in a letter. "Your false accusations have caused irreparable harm to" Greene and to Taylor Commercial.

John Cowan / Instagram

Cowan's lawyer, Bryan Tyson, shot back with his own letter standing by the ad and said the Wood letter essentially proves their statements were true that Greene refused to use E-Verify when she was leading the company. Though no dates were used in the ad, Cowan's team said their ad was referencing Taylor Commercial's E-Verify record before 2010.

Greene purchased Taylor Commercial from her father in 2002. State annual registration documents show Greene was listed as the company's CFO each year from 2003 to 2010, Cowan's campaign said. And now Greene acknowledges the E-Verify program didn't come online until 2010 as she was leaving company leadership, Cowan's lawyer argues.

"As a result, the statement that Taylor Commercial did not use E-Verify while Ms. Greene was leading the company is factually correct based on filings by Taylor Commercial with the Secretary of State. Your letter confirms the truthfulness of this statement," Tyson wrote.

Cowan's campaign manager Spencer Hogg said Greene's complaint is "baseless" and blasted her "bullying efforts" to silence her political opponents who "tell the truth."

The Cowan campaign put out a press release titled: "Greene confirms she didn’t use E-Verify while construction company executive" adding that "Oops! Candidate admits her company didn’t care about illegal immigration for nearly a decade."

GOP CONGRESSIONAL CANDIDATE BLOWS UP 'SOCIALISM' IN NEW TV AD

A second Greene lawyer, David Guldenschuh, responded Thursday that regardless of what the business records say, Greene has been leading the company as its majority owner since 2002 and when she was listed as CFO she voluntarily enrolled the company in E-Verify on Aug. 5, 2010, three years ahead of any requirement to do so. The second letter to Cowan's campaign points out that E-Verify didn't come into existence until 2007 and it's impossible for Greene to "refuse" to enroll in a program that was voluntary until the 2013 legal requirement.

"Your clever attempt to pigeon-hole your defamatory statements by claiming that it only refers to the period 2003-2010 is laughable and will be easily destroyed when presented to a jury," Guldenschuh wrote.

In a new ad, Greene then went on to accuse Cowan of failing to use E-Verify for his business, Cortex Toys, which she says has shipped jobs off to "Communist China."

"The real hypocrisy of this lie and attack on me and my company is the fact that John Cowan does not have any of his companies registered on E-verify," Greene said. "His own toy company, Cortex Toys, which manufactures its toys in China and operates out of a warehouse in Rome, Ga., is not registered on E-verify. So not only does John Cowan send American jobs overseas, he also does not verify [the] legality of citizenship of employees here in the U.S."

Cowan's campaign, however, dismissed Greene's counterclaim as a "diversionary tactic."

"John’s toy company has two 1099 contractors who perform services for the company. In other words, they aren’t his employees. This is a well-established, widely agreed-upon distinction," Hogg said.

Cowan's campaign manager also said Cowan sourced USA-made products when available.

"John’s company never manufactured anything in China. It bought and sold toys for children’s brain development. It sourced domestically whenever American made products were available. The fact she’s talking about sending jobs overseas and warehouse workers that don’t exist shows she’s just throwing blind punches," Hogg continued.

The Cowan campaign called out Greene's new ad claim that she "always" used E-Verify, which they argue contradicts her lawyer's letter that said Taylor Commercial didn't enroll until 2010.

"To lie so brazenly with an assertion disproved by federal records and her own legal henchmen leaves us with no reason to believe she ‘never’ hired an illegal immigrant in her construction company," Hogg said. "With 50-100 employees, in that industry in particular, it’s impossible to say never when she wasn’t using E-verify.”

Northwest Georgia's 14th congressional district seat is open after GOP Rep. Tom Graves announced he won't seek reelection. In the June 9 primary, Greene came in first among the nine candidates vying for the Republican nomination, with 40 percent of the vote. Cowan was a distant second at 21 percent.

Greene earned a congratulatory tweet from Trump on July 12 calling her a "big winner." But with no candidate breaking 50 percent, Greene and Cowan will face off in a run-off election Aug. 11.

Since her win, Greene has come under increased security and attacks after past social media videos showed her support of QAnon conspiracy theories and espousing views that have been condemned as racist, Islamophobic and anti-Semitic. Cowan has tried to capitalize on the moment and promised he'll be a conservative voice in Congress with "none of the embarrassment."

Politico reported that in the Facebook Live videos Greene suggested that Muslims do not belong in government; thinks Black people “are held slaves to the Democratic Party”; called George Soros, a Jewish Democratic megadonor, a Nazi; and said she would feel “proud” to see a Confederate monument if she were Black because it symbolizes progress made since the Civil War.

REPUBLICAN REVENGE: RECORD GOP FIELD FORMS, ON 2020 MISSION TO TAKE DOWN 'SOCIALISTS'

Several prominent Republicans have expressed disgust for Greene's comments, including House Minority Leader Kevin McCarthy, of California, Rep. Jody Hice, of Georgia, who withdrew his support for Greene, and Minority Whip Steve Scalise, of Louisiana, who threw his support behind Cowan.

“The comments made by Ms. Greene are disgusting and don’t reflect the values of equality and decency that make our country great,” Scalise said in a statement to Politico. “I will be supporting Dr. Cowan.”

Greene hasn't backed down. She rejected the attacks against her and blasted "spineless" Republicans who won't fight back. She blamed the "fake news" media for twisting her words into a false narrative and likened the attacks on her to the scrutiny Trump has received from reporters trying to undermine his agenda with the "Russian collusion conspiracy," she said.

"The Fake News Media, the DC Swamp, and their radical leftist allies see me as a very serious threat. I will not let them whip me into submission," Greene tweeted.

The 14th district is solidly red. Whoever wins the Greene-Cowan runoff next month is all but certain to head to Congress next year.