AP Photo/John Minchillo, File
"Megyn Kelly has no conflict of interest. Donald Trump is just trying to build up the audience for Thursday's debate, for which we thank him," a Fox News spokesperson told Business Insider on Saturday.
Earlier in the day, Trump declared on Twitter that Kelly had a "conflict of interest," and therefore "should not be allowed to be a moderator of the next debate."
Trump further criticized Kelly at a Saturday-afternoon campaign rally.
"She's very biased. She's very biased. She has a conflict I think. Her hatred and her bias, I think, gives her a conflict. So maybe she'll drop out as a professional. And she's a professional," he told his supporters in Pella, Iowa.
Trump has raged against Kelly since last August, when she was one of three moderators at the first Fox-hosted primary debate. Kelly infuriated Trump at the time by asking a rather pointed question about disparaging comments he's made about women's looks.
Fox News told The Los Angeles Times in August that the three moderators of that debate - Kelly, as well as Fox anchors Bret Baier and Chris Wallace - would be returning to moderate the network's January debate.
Since then, Trump has waged an on-again-off-again war against Fox News, with many of his attacks aimed at Kelly. Trump drew backlash after twice promoting tweets calling Kelly a "bimbo." He also once criticized Kelly with an infamous comment that many interpreted as a crude reference to menstruation. Trump claimed he was being misinterpreted.
Kelly has declined to respond directly to Trump's frequent attacks, though the real-estate mogul has fumed on Twitter when she hosted his critics on "The Kelly File," though she also interviews his supporters.