NEW YORK (AP) — Former President Donald Trump sued the key witness in his criminal case on Wednesday, accusing onetime lawyer and fixer Michael Cohen of "vast reputational harm" for talking publicly about the hush-money payments at the heart of the case.

The lawsuit, filed in Miami, offered a preview of arguments that are sure to be featured in Trump's defense against charges that he falsified internal business records to disguise payments made during the 2016 presidential campaign to silence claims of extramarital sexual encounters.

The suit accused Cohen of breaking a confidentiality agreement he signed as a condition of his employment, violating ethical standards for lawyers and "spreading falsehoods" about Trump "with malicious intent and to wholly self-serving ends." It seeks over a half-billion dollars from Cohen.

Trump isn't specifically suing Cohen over his grand jury testimony in the criminal case, but he cites it in support of an argument that his ex-lawyer sought to profit from his role through the publication of two books, a podcast series and media appearances.

Cohen's spokesman, attorney Lanny Davis, said the lawsuit will not deter Cohen's cooperation with prosecutors.

"Mr. Trump appears once again to be using and abusing the judicial system as a form of harassment and intimidation against Michael Cohen," Davis said. "It appears he is terrified by his looming legal perils and is attempting to send a message to other potential witnesses who are cooperating with prosecutors against him."

The suit is the latest effort by Trump to use the legal system to go after his political enemies and is another example of the former president turning on a once-loyal aide after their relationship imploded.

A judge in Florida sanctioned Trump and one of his attorneys in January, ordering them to pay nearly $1 million for filing what he said was a bogus lawsuit against Trump's 2016 rival Hillary Clinton and others.

Davis predicted this lawsuit would also fail.

"Is there anyone in America, aside from a shrinking minority base of believers, who takes Mr. Trump seriously when he files these apparently frivolous lawsuits?" Davis asked.

The criminal case against Trump, brought last week by Manhattan District Attorney Alvin Bragg, accuses the former president of falsifying 34 business records at his company to hide the true nature of 11 checks paid to Cohen to reward him for work covering up Trump's extramarital affairs.

Those checks, prosecutors said, reimbursed Cohen for a $130,000 payment he made on Trump's behalf to porn actor Stormy Daniels, who had been in negotiations to sell her story of an alleged sexual encounter with the Republican. Cohen also played a role in arranging payments to the Playboy model Karen McDougal and to a Trump Tower doorman.

Trump pleaded not guilty to the charges and says the alleged encounters with Daniels and McDougal never happened.

Bragg's office on Wednesday declined to comment on Trump's lawsuit against Cohen.

Cohen pleaded guilty in 2018 to tax evasion, lying to Congress, and campaign finance violations regarding the payments to Daniels and McDougal. He was sentenced to three years in prison, although the arrival of the COVID-19 pandemic enabled him to serve the majority of the sentence under house arrest.

Although federal prosecutors referenced Trump in the charges against Cohen, they chose not to pursue a criminal case against the Republican. Neither did investigators in the office of special counsel Robert Mueller, who conducted a wide-ranging probe through much of Trump's presidency.