Megyn Kelly of Fox’s The Kelly File is set to moderate the upcoming Republican presidential debate alongside Chris Wallace and Bret Baier on January 28 in Iowa, and Donald Trump is calling foul.

Taking to Twitter to make his case, Trump said he doesn’t think Megyn Kelly should be allowed to moderate the debate.

Based on @MegynKelly's conflict of interest and bias she should not be allowed to be a moderator of the next debate.

— Donald J. Trump (@realDonaldTrump) January 23, 2016

Donald Trump and Megyn Kelly have been at odds with one another since August when she first confronted him about comments he’d made against women in the past–calling them “fat pigs” and “slobs.”

Shortly thereafter, during a conversation with Don Lemon on CNN, Donald Trump bashed Megyn Kelly, saying she had “blood coming out of her eyes” and “blood coming out of her whatever,” which no doubt referred to her menstrual cycle. Trump later said only a “deviant” would think he was talking about Megyn Kelly’s menstrual cycle.

Fox News defends Megyn Kelly after Donald Trump says she shouldn't be 'allowed' to moderate the next debate https://t.co/cc3WhWVCGj

— Business Insider (@businessinsider) January 23, 2016

Even though he has toned things down a bit where Megyn Kelly is concerned, he still gets in digs whenever and wherever he can, and retweets anyone who talks negatively about her or The Kelly File.

Does Donald Trump fear Megyn Kelly will trip him up at this last debate before the Iowa caucus? Is that why he doesn’t want her serving as one of the moderators?