Michael Cohen, who once said he would “take a bullet” for Donald Trump, is expected to tell Congress in a blistering testimony Wednesday that the president is a “racist,” a “con man,” and a “cheat” who “knew about the release of the hacked Democratic National Committee e-mails ahead of time”—an explosive allegation that directly links Trump to illegal activity by Roger Stone.

“In July 2016, days before the Democratic convention, I was in Mr. Trump’s office when his secretary announced that Roger Stone was on the phone,” Cohen is expected to tell the House Oversight Committee Wednesday, according to his prepared remarks. “Mr. Trump put Mr. Stone on the speakerphone. Mr. Stone told Mr. Trump that he had just gotten off the phone with Julian Assange and that Mr. Assange told Mr. Stone that, within a couple of days, there would be a massive dump of e-mails that would damage Hillary Clinton’s campaign.”

“Mr. Trump responded by stating to the effect of ‘wouldn’t that be great,’” Cohen recalls.

Stone, a close confidant of the president, was indicted last month on charges of obstruction, making false statements, and witness tampering, all stemming from his shady contacts with WikiLeaks. Cohen’s allegations that Trump knew of and seemingly encouraged that activity runs counter to the White House’s claim that special counsel Robert Mueller’s charges against Stone have “nothing to do with the president.”

Anticipating Cohen’s heavily critical testimony, Trump and his team have sought to undercut his credibility. “He is lying in order to reduce his prison time,” the president tweeted Wednesday from Vietnam, where he is holding his second summit with North Korean strongman Kim Jong Un.

In his statement, Cohen acknowledges having lied in the past, but says he did so at the behest of his client. And while he is not expected to present hard evidence to support his claim that Trump knew of Stone’s coordination with WikiLeaks, he is expected to present Congress with a copy of a check written by the president to reimburse him for his hush agreement with Stormy Daniels. Cohen, who pleaded guilty to campaign-finance violations for his effort to bury the adult-film star’s claims of an affair with Trump, said last year that he did so “at the direction of and in coordination with” the president. He is expected to go into greater detail on Wednesday, explaining how Trump instructed him to use his own funds to pay Daniels to avoid the money being traced back to his campaign, and to lie about the alleged affair—including to First Lady Melania.

“I am going to jail in part because of my decision to help Mr. Trump hide that payment from the American people before they voted a few days later,” Cohen says in his opening statement, which also outlines Trump’s involvement in plans for a Trump Tower in Moscow long after he said they’d been disbanded.

Cohen lied about the nature and timing of those discussions in his last appearance before Congress, and implies that Trump indirectly ordered him to do so. “In his way, he was telling me to lie,” Cohen is expected to say.

Those allegations all underscore and may add to the president’s legal and political vulnerability. But Cohen’s testimony doesn’t just outline potentially criminal activity on the part of the president; the longtime fixer also provides a damning assessment of Trump’s character, telling Congress that he’s even more of a lying, cheating racist in private than he is in public.