The People of the State of New York v. Donald J. Trump, et al, is scheduled to get underway in lower Manhattan at 10 a.m. with opening statements.

If opening statements are completed before the end of the day, the New York attorney general plans to begin her case by calling Trump's former Mazars USA accountant Donald Bender to the stand.

Mazars severed its business relationship with the former president last year after learning of the attorney general's findings during the AG's probe.

Though Trump has denied all wrongdoing alleged by the attorney general, Judge Arthur Engoron has already decided the central allegation against Trump and his co-defendants, ruling in a pretrial hearing last week that the AG had provided "conclusive evidence" that Trump overvalued his assets between $812 million and $2.2 billion.

The judge then canceled the Trump Organization's business certificates in New York, severely restricting Trump's ability to conduct business in the state moving forward -- a move that Trump attorney Alina Habba called "nonsensical" and "outrageously overreaching."

"In defendants' world: rent regulated apartments are worth the same as unregulated apartments; restricted land is worth the same as unrestricted land; restrictions can evaporate into thin air," Engoron wrote, citing multiple arguments made by defense to justify the allegedly inflated valuations of Trump's assets. "That is a fantasy world, not the real world."

Among the issues still to be determined at trial: What additional penalties Trump might face, and what might happen with the multiple causes of action included in the attorney general's suit.

Former President Donald Trump stepped up his attacks on the judge overseeing and deciding his case, writing on Truth Social overnight that Justice Arthur Engoron should resign and be sanctioned for "abuse of power."

Similar to an earlier post, Trump criticized allegations regarding the value of his Mar-a-Lago estate, in addition to an appellate court's ruling that his lawyers unsuccessfully tried to use to limit the timeframe of the case.

Former President Trump posted on his Truth Social platform Sunday night that he intends to attend the opening of the trial.

"See you in court -- Monday morning," he wrote in a post.

Earlier Sunday, multiple sources familiar with the decision told ABC News that Trump was expecting to attend.

Trump will have no speaking role in court on Monday, but it is anticipated that he'll return to the courthouse toward the end of the state's case when court records show he will be called as a witness.

Former President Trump appears to be done watching his civil fraud trial, and he had a lot to say about it on his way out of the courthouse.

Speaking to reporters, Trump renewed his attacks on Judge Engoron and accused the "whole system" of being rigged against him while referencing the criminal charges he faces in Washington, D.C., and Fulton County, Georgia.

"Our whole system is corrupt. This is corrupt. Atlanta is corrupt, and what's coming out of DC is corrupt," Trump said.

Trump again claimed that his net worth is more than is represented in his financial documents, and said that his Mar-a-Lago estate is worth "50 to 100 times more" than what Engoron determined.

Trump also resumed attacks on the judge -- who he said is "run by the Democrats" -- and New York Attorney General Letitia James, who he alleged is communicating with the Department of Justice to "keep me nice and busy."

The former president said he's been "stuck" in court when he would rather be campaigning in early primary states.

Asked by ABC News why he attended the trial despite no obligation to do so, he claimed his attendance was necessary to expose corruption to the press.

"Why attend? Because they want to point it out to the press how corrupt it is, because nobody else seems to be able to do it," Trump said.

Trump departed the courthouse and is not expected to return to court for the afternoon session.