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.

Judge Engoron fined former President Trump $10,000 for violating a limited gag order after deciding that Trump referred disparagingly to his law clerk during a statement in the hallway.

Trump briefly took the witness stand, raising his hand and stating his name, "Donald John Trump, New York."

Engoron asked Trump, "Did you say, 'This judge is a very partisan judge with a person who is very partisan sitting alongside of him?'"

Trump responded "Yes," but insisted he was referring to Michael Cohen, who was seated next to the judge in the witness chair.

"You sure you didn't mean the person on the other side?" Engoron asked, referring to his law clerk, whom Trump previously disparaged in a social media post that the judge ordered him to take down as part of the limited gag order he imposed earlier in the trial.

"Yes, I'm sure," Trump answered.

Trump conceded his social media post was "maybe unfair" but he added he thinks "she's very unfair."

Engoron decided Trump's hallway statement must have referred to his clerk because "there's a barrier" between the bench and Cohen, and he suggested Trump would have called Cohen by name.

The defense immediately balked at the fine.

"I just don't think there's any clear record here," defense attorney Chris Kise said.