President Trump’s onetime personal lawyer, Michael D. Cohen, is expected to accuse his former boss of lying, making racist comments and engaging in potentially criminal conduct since assuming office, media reports say.

Cohen is scheduled to testify before the House of Representatives oversight committee Wednesday in a public appearance that is expected to focus on alleged misdeeds by Trump during his presidential campaign and after his election. The highly anticipated, and possibly explosive, hearing will be broadcast on national television. Cohen is also set to be questioned by the Senate and House intelligence committees on Tuesday and Thursday, but those sessions will take place behind closed doors.

Reports in The New York Times, Wall Street Journal and Reuters quote unnamed sources as saying that Cohen will allege that Trump lied about his wealth, used racist language and, after becoming president, reimbursed Cohen for hush-money payments the lawyer made to porn actress Stormy Daniels to keep quiet a sexual encounter between her and Trump. Cohen paid Daniels, whose real name is Stephanie Clifford, $130,000 in October 2016 during the final days of the presidential race.

Cohen has pleaded guilty to a campaign finance-related charge stemming from that payoff. He is scheduled to begin serving a three-year prison sentence in May in connection with that payment and for other crimes.

Although he once said he would “take a bullet” for Trump, Cohen has since turned on his former client and pledged to tell the truth about Trump’s actions and alleged wrongdoing. The reports say he will detail the reasons for his change of heart in his appearance before lawmakers. The White House has been bracing for Cohen’s congressional testimony and has characterized him as a loser and a liar.

According to the reports, Cohen will allege that Trump deliberately misstated his wealth on various occasions, exaggerating or downplaying it as he felt served his interests – for example, to avoid paying taxes. Cohen will also say that Trump kept inquiring about the Trump Tower project in Moscow well into his presidential campaign, maintaining a personal interest in the venture despite running for the highest office in the land.

Regarding the payment to Daniels, Cohen is expected to say that it was at Trump’s instigation. He implicated Trump in the hush payment scheme when he first pleaded guilty in August to a series of charges that included campaign finance violations.

Cohen also entered a guilty plea in November to making false statements to Congress about the timeline of efforts to secure a deal to build the Moscow Trump Tower. He told Special Counsel Robert Mueller that he discussed the project multiple times with Trump – who is identified in court documents as “Individual 1” – as well as with Trump family members.

Cohen is expected to come to the congressional hearing with documents and other visual aids to support his contentions. Trump will not be in Washington while his former lawyer testifies, but will instead be in Vietnam for his summit with North Korean leader Kim Jong-un.

Cohen claimed that Trump used racist language in an interview in November with Vanity Fair.

The scope of Wednesday’s public hearing will not include questions related to Russian efforts to influence the 2016 election. In a memo issued last week, Rep. Elijah Cummings (D-Md.), the chairman of the House Oversight Committee, said the scope of the hearing will include the president’s “payoffs, financial disclosures, compliance with campaign finance laws, business practices, and other matters.”

Ted Johnson contributed to this report.