Top Trump campaign officials warned the nonpartisan presidential debate commission last month that President Trump could snub the debates if the moderator choices and process are not deemed “fair.”

The December conversation included Trump campaign manager Brad Parscale, campaign operating officer Michael Glassner, and Frank Fahrenkopf, the co-chairman of the Commission on Presidential Debates, according to the Washington Post.

The meeting happened as Trump attacked the commission on Twitter and considered whether he would sit out of the three debates scheduled for the fall.

Parscale complained to Fahrenkopf that the board of directors was anti-Trump and that he wanted the commission to select debate moderators who were viewed as impartial to Trump.

“We want to have debates that are fair and are more geared toward informing the American people than to boosting the careers of the moderators,” campaign spokesman Tim Murtaugh said.

Parscale has since discussed with other aides about trying to hold debates outside the commission.

Trump has told his advisers that he does not trust the commission and worries about the moderators. He repeatedly complained about the debates in the 2016 general election, which gave Hillary Clinton a boost in the polls after each of their matchups.

Trump blamed a “defective mic” and questioned whether it was done “on purpose” to help Clinton after his debate performance in September 2016 was criticized. The commission acknowledged that a technical malfunction affected the volume of his microphone during the debate, but only in the debate hall and not on the broadcast of the event.

His debate team also clashed with the commission over a group of women who accused President Bill Clinton of sexual assault and sexual harassment. Trump’s campaign invited the women to the second debate against Hillary Clinton and wanted them seated in the VIP box, where the former president would have to walk past them. The commission threatened to have the women removed if they sat in Trump’s box. The VIP box is exclusively family seating, according to the commission.

Debate officials said they would stay in touch with Trump’s team but did not yield control over the board of directors or the choice of moderators.

Former Republican Sens. John Danforth of Missouri and Olympia Snowe of Maine, former Democratic congresswoman Jane Harman, and former Time Warner chief executive Richard Parsons are on the board. Commission rules prohibit members from supporting or contributing to political candidates.

The commission has already scheduled the dates and locations for three presidential debates: Sept. 29 at the University of Notre Dame, Oct. 7 at the University of Utah, and Oct. 15 at the University of Michigan.

Presidential debates have occurred every year since 1976, when Republican President Gerald Ford faced Democratic challenger (and winner) Jimmy Carter. The first presidential debates took place in 1960 between Democratic candidate John F. Kennedy and Republican challenger Richard Nixon.