The Republican National Committee is threatening to prohibit its future nominees from participating in presidential debates if the organization behind them does not agree to certain reforms.

In a letter addressed to the Commission on Presidential Debates on Thursday, RNC chairwoman Ronna McDaniel outlined concerns as to “whether the CPD credibly can provide a fair and impartial forum for presidential debates.”

“So long as the CPD appears intent on stonewalling the meaningful reforms necessary to restore its credibility with the Republican Party as a fair and nonpartisan actor, the RNC will take every step to ensure that future Republican presidential nominees are given that opportunity elsewhere,” McDaniel wrote in the letter. “Accordingly, the RNC will initiate the process of amending the Rules of the Republican Party at our upcoming Winter Meeting to prohibit future Republican nominees from participating in CPD-sponsored debates.”

The reforms proposed include establishing term limits for CPD’s board of directors, holding at least one debate before the start of early voting, enacting a code of conduct preventing CPD staff from endorsing a candidate, setting transparent criteria for the selection of moderators and putting in place more transparent guidelines for conducting debates.

Former president Donald Trump often accused CPD of being biased against him during the 2016 and 2020 elections. He pulled out of a debate in October 2020 that was made virtual after he tested positive for COVID-19, calling the format “not acceptable.”

CPD has been sponsoring presidential debates since 1988, and is independent of any political party. In a statement to the New York Times, the organization said: “The CPD deals directly with candidates for president and vice president who qualify for participation. The CPD’s plans for 2024 will be based on fairness, neutrality and a firm commitment to help the American public learn about the candidates and the issues.”