"He’s not afraid to take a question," he told ABC News' George Stephanopoulos on "Good Morning America" today.
"The issue is an issue of fairness," he added, claiming that Fox News anchor Megyn Kelly was "obsessed" with Trump. "It's not appropriate to have someone like that on the debate stage," he continued. "It's impossible to have a fair and honest debate."
When asked whether it's possible that Trump shows up to the debate, Lewandowski said "the short answer, I don't think so."
But Fox News said it isn't backing down from Kelly's questioning on Trump's comments about women. "I maintain it was a tough but fair question and we agreed to disagree," Kelly said last night on her show.
"Capitulating to politicians’ ultimatums about a debate moderator violates all journalistic standards," a Fox News spokesperson said in a statement, adding that Trump is still welcome at the debate. "We can’t give in to terrorizations toward any of our employees."
Fox also said in their statement that Lewandowski told network leaders that Kelly "had a 'rough couple of days after that last debate' and he 'would hate to have her go through that again,'" adding that he continued to make "threats."
After Trump originally equivocated on attending the debate, which Kelly is slated to moderate, the candidate opened up a Twitter poll asking whether he should attend.
The network then released a statement saying: “We learned from a secret back channel that the Ayatollah and Putin both intend to treat Donald Trump unfairly when they meet with him if he becomes president -- a nefarious source tells us that Trump has his own secret plan to replace the Cabinet with his Twitter followers to see if he should even go to those meetings.”
Lewandowski also told Stephanopoulos that the debate will likely have fewer viewers without Trump.