Former national security adviser John Bolton is making it hard on Republicans in the Senate who want to act as if President Donald Trump has done nothing wrong in his dealings with Ukraine. Bolton’s potential testimony has hung over the impeachment effort since the outset, since he is a witness with true inside knowledge of the machinations of the Trump foreign policy apparatus, but an appearance before Congress had looked increasingly less likely to take place—until excerpts of his upcoming book started leaking on the West Wing like a fire sprinkler. First came Bolton’s assertion in the book’s manuscript that Trump personally and explicitly linked releasing Ukrainian military aid to Kiev digging up dirt on his political rival Joe Biden. Now, the New York Times reports a draft of Bolton’s book recounts a conversation between the then–national security adviser and Attorney General Bill Barr over apparently mutually held “concerns that President Trump was effectively granting personal favors to the autocratic leaders of Turkey and China.”

Bolton submitted a draft of his book to the White House for review nearly a month ago, according to the Times, which means the administration knows exactly how damaging it could be. This latest fire alarm, of which there will certainly be more, comes from a conversation between Bolton and Barr where both expressed concern about Trump’s behavior when dealing with autocrats, particularly Turkey’s President Recep Tayyip Erdogan and President Xi Jinping of China. Bolton said he told Barr that Trump’s behavior amounted to “effectively granting personal favors” to the leaders. Bolton said Barr responded that Trump appeared to make promises to interfere with independent Department of Justice investigations into Turkish and Chinese companies at the behest of the two leaders.

“Bolton wrote in the manuscript that Mr. Barr singled out Mr. Trump’s conversations with Mr. Xi about the Chinese telecommunications firm ZTE, which agreed in 2017 to plead guilty and pay heavy fines for violating American sanctions on doing business with North Korea, Iran and other countries. A year later, Mr. Trump lifted the sanctions over objections from his own advisers and Republican lawmakers,” the Times reports. “Mr. Barr also cited remarks Mr. Trump made to Mr. Erdogan in 2018 about the investigation of Halkbank, Turkey’s second-largest state-owned bank. The Justice Department was scrutinizing Halkbank on fraud and money-laundering charges for helping Iran evade sanctions imposed by the Treasury Department.” After multiple personal appeals to Trump to intercede in the matter, Erdogan told reporters in 2018 that Trump had agreed to help resolve the investigation.

“There was no discussion of ‘personal favors’ or ‘undue influence’ on investigations, nor did Attorney General Barr state that the President’s conversations with foreign leaders was improper,” a Justice Department spokeswoman said in a statement Tuesday. “If this is truly what Mr. Bolton has written, then it seems he is attributing to Attorney General Barr his own current views—views with which Attorney General Barr does not agree.”