Top White House aides were certain that Vice President Mike Pence would support the use of the 25th Amendment to remove President Trump from office due to mental incapacity after former FBI Director James Comey’s firing, according to a new book reportedly written by an anonymous current or former senior administration official. The book, A Warning, which is written under the pen name Anonymous, claims that White House officials did a tally of which Cabinet members would be willing to sign a letter to invoke Section 4 of the 25th Amendment, allowing executive officials to declare the president unfit for office and granting the vice president the role. HuffPost reports the letter would be signed by the majority of the Cabinet, as well as the vice president, before it would be submitted to Congress. According to Anonymous, senior officials were sure that Pence would support the move if a majority of the Cabinet signed off on the letter.

The claim could not immediately be independently verified, but Pence has previously denied taking part in discussions about the 25th Amendment. The topic first arose in September 2018, when The New York Times published an anonymous op-ed reportedly written by a “a senior official in the Trump administration” who said that invoking the 25th Amendment had been discussed by senior administration officials. After the op-ed was published, Margaret Brennan, moderator of CBS’s Face the Nation, asked Pence if he had been a part of the discussions. Pence said, “No, never. And why would we be, Margaret?”