Fox News and its powerful owner, Rupert Murdoch, face a second major libel suit over the network’s coverage of the 2020 presidential election, a new front in the growing litigation over media disinformation and its aftermath.

In the recent aftershock of Donald J. Trump’s attempt to undermine President Biden’s victory, Dominion Voting Systems, an electoral technology company at the center of an unsubstantiated pro-Trump conspiracy theory about rigged voting machines, filed a lawsuit on Friday in Fox News has been accused of promoting lies that ruined its reputation and business.

Dominion, who has filed for a lawsuit, is seeking at least $ 1.6 billion in damages. Less than two months ago, another electoral technology company, Smartmatic, filed a $ 2.7 billion lawsuit against Murdoch’s Fox Corporation, naming Fox anchors Maria Bartiromo, Lou Dobbs and Jeanine Pirro as defendants.

In a 139-page complaint filed with the Delaware Supreme Court, Dominion depicted Fox as an active participant in spreading false claims that the company changed the number of votes and tampered with its machines to aid Mr. Biden in the election.

These falsehoods were relentlessly promoted in public forums, including appearances on Fox programs, by Mr. Trump’s attorneys, Rudolph Giuliani and Sidney Powell.

In January, Dominion sued Mr. Giuliani and Ms. Powell on charges of defamation. The company also sued Mike Lindell, the executive director of MyPillow and an ally of Trump’s who was a frequent guest at Fox and other conservative media outlets. Each of these lawsuits seek damages in excess of $ 1 billion.

“The truth matters,” wrote Dominion’s attorneys in Friday’s complaint against Fox. “Lies have consequences. Fox sold a false story of electoral fraud for its own commercial purposes, seriously injuring Dominion in the process. If this case does not result in defamation by a broadcaster, it does nothing. “

In a statement on Friday, Fox said the coverage of the 2020 election “is in the highest tradition of American journalism” and pledged to “vigorously defend this unsubstantiated lawsuit in court.”

Dominion’s filing opened a new phase in the battle against the critics, and Thomas A. Clare, an attorney who represents the company, said Fox’s lawsuit was unlikely to be the final legal action. Susman Godfrey law firm, known for bringing cases to court, recently partnered with Mr. Clare’s law firm to support Dominion’s case.

Fox Corporation has filed a motion to dismiss the Smartmatic lawsuit, arguing that the false claims of election fraud on its channels were part of coverage of a short-lived story of significant public interest.

“A sitting president’s attempt to question the outcome of an election is objectively newsworthy,” Fox wrote in the motion.

The tale that Mr. Trump and his allies made about Dominion was one of the baroque creations of a month-long effort to cast doubt on the 2020 election results and convince Americans that Mr. Biden’s victory was illegitimate.

Founded in 2002, Dominion is one of the largest voting machine manufacturers in the United States. More than two dozen states, including several owned by Mr. Trump, used their equipment over the past year.

Mr. Trump’s allies falsely portrayed Dominion as biased against Mr. Biden, arguing without evidence that it was linked to Hugo Chavez, the long-dead Venezuelan president. Dominion founder John Poulos and other employees received harassing and threatening messages from people who believed the company had undermined the election results, according to the complaint.

Fox News and Fox Business programs were part of the mass media in which supporters of Mr. Trump denounced Dominion. The lawsuit also cites examples of Fox hosts, including Ms. Bartiromo and Mr. Dobbs, being uncritically repeated or vouching for false claims made by Mr. Giuliani and Ms. Powell.

“Fox took a small flame and turned it into a forest fire,” wrote Dominion in the lawsuit, adding that the network “gave these fictions a meaning they would otherwise never have achieved.”

Dominion attorneys also cited an unusual argument by Ms. Powell on Friday in a motion filed Monday to dismiss Dominion’s separate lawsuit against her.

In that motion, her lawyers alleged that “no sane person” would accept Ms. Powell’s allegations as facts because the political language is often imprecise. The motion essentially argues that their claims about Dominion’s voting machines were hyperbolic and therefore not defamatory.

Mr. Clare described Ms. Powell’s allegation as “ridiculous,” but said her acknowledgment that her allegations were not factual may prove relevant to Dominion’s lawsuit. “Fox knew these were lies, but they made a conscious choice to pass them on to their huge audience,” Clare said on a call to journalists.

Dominion said it recently lost key contracts with election officials in Georgia and Louisiana, adding that the company now faces “the hatred, scorn and distrust of tens of millions of American voters”.

Defamation battles are a relatively novel tactic in the fight against disinformation, but they have produced some early results.

In February, two days after Smartmatic filed its lawsuit, Fox Business canceled its highest-rated program, Lou Dobbs Tonight. An anchor on Newsmax – a pro-Trump cable channel that received letters from Dominion and Smartmatic warning of imminent legal action – interrupted an interview with Mr Lindell after the MyPillow founder began attacking Dominion.

Combined, Dominion and Smartmatic are seeking at least $ 4.3 billion in damages from Fox. Fox Corporation, which is controlled by Mr. Murdoch, 90) and his older son Lachlan, said it had pretax profits of $ 3 billion on sales of $ 12.3 billion from September 2019 to September 2020 .

As a large media organization, Fox News enjoys solid protection under First Amendment case law, which often protects newspapers and broadcasters from being held liable for claims made by interviewees. If a court found Dominion to be a public figure, its attorneys would have to show that Fox acted with “real malice” and “reckless disregard” for the truth, which is usually a high standard.

“There is concern that putting Fox under liability could lead to the suppression of information about which people have a strong interest,” said Timothy Zick, a professor at William and Mary Law School, who referred to the law first Specializes in change.

In its lawsuit on Friday, Dominion argued that Fox had an incentive to spread falsehoods about a rigged election, in part to reassure pro-Trump viewers who were upset about the network’s early projection that Mr. Biden would wear Arizona .

Dominion also claims that Fox and its hosts have benefited from uncritically reiterating these baseless claims. The lawsuit cites a surge in ratings for anchors like Ms. Bartiromo and Mr. Dobbs after the election, noting that Ms. Pirro’s ex-husband, who spoke on the air of a stolen election, later received a pardon from Mr. Trump.

Fox has argued that its coverage of the election should be viewed in its entirety, noting that at least one host, Tucker Carlson, was skeptical of Ms. Powell’s statements. The network has also said that allegations made by the president’s lawyers in an electoral battle were inherently timely.

Freedom of expression experts said Fox was forced to defend its journalism more fully than the particular claims it made about Dominion and Smartmatic.

“Fox had a problem because many of its experts said the very things that prompted Dominion to bring this lawsuit,” prominent First Amendment attorney Floyd Abrams said in an interview.