Donald Trump relaunched his bitter war of words with Fox News anchor Megyn Kelly Monday night, blasting her return to the air after a vacation.

“I liked The Kelly File much better without @megynkelly,” Trump tweeted. “Perhaps she could take another eleven day unscheduled vacation!”

Roger Ailes, the chairman and CEO of Fox News, came to Kelly’s defense on Tuesday.

“Donald Trump’s surprise and unprovoked attack on Megyn Kelly during her show last night is as unacceptable as it is disturbing,” Ailes said in a statement. “Megyn Kelly represents the very best of American journalism and all of us at Fox News Channel reject the crude and irresponsible attempts to suggest otherwise. I could not be more proud of Megyn for her professionalism and class in the face of all of Mr. Trump’s verbal assaults. Her questioning of Mr. Trump at the debate was tough but fair, and I fully support her as she continues to ask the probing and challenging questions that all presidential candidates may find difficult to answer. Donald Trump rarely apologizes, although in this case, he should.”

A Fox spokesperson said earlier this month that Kelly’s vacation was preplanned.

“The conspiracy theories about Megyn Kelly’s vacation rank up there with UFOs, the moon landing and Elvis being alive. Megyn is on a pre-planned, annual summer vacation with her family, which is much deserved,” the spokesperson said. “To imply otherwise as Donald Trump and his campaign operatives have is not only wildly irresponsible, but downright bizarre.”

The Republican candidate’s critique of Kelly was the latest in a revenge campaign since the two clashed over the GOP presidential debate on Aug. 6.

He tuned in Monday night to attack her return to the anchor desk.

“@megynkelly must have had a terrible vacation, she is really off her game,” Trump lamented. “Was afraid to confront Dr. Cornel West. No clue on immigration!”

Trump supporters also chimed in with an online onslaught against Kelly. The Donald retweeted one hater who said, “The bimbo back in town.”

Kelly has insisted she would not back down on The Donald.

“I certainly will not apologize for doing good journalism,” Kelly said days after the debate. “So I’ll continue doing my job without fear or favor.”