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.

An attorney for Judge Arthur Engoron also filed in support of the gag order in Donald Trump's civil fraud trial, arguing that violent threats have increased since the gag order was lifted.

The limited gag order, which prohibited Donald Trump and his attorneys from publicly commenting about Engoron's staff, was issued by the judge last month after Trump posted about the judge's law clerk on social media. Judge David Friedman of the appellate division's First Department stayed the order on Thursday, citing constitutional concerns over Trump's free speech rights.

Engoron's filing includes a report from Charles Hollon of the Judicial Threats Assessment Unit of the New York State Court System's Department of Public Safety. According to the report, Engoron and his principal law clerk, Allison Greenfield, have been inundated with credible, violent and antisemitic threats since Trump began criticizing Greenfield.

"The threats against Justice Engoron and Ms. Greenfield are considered to be serious and credible and not hypothetical or speculative," Hollon wrote in the report.

Greenfield has been the victim of daily doxing of her personal email address and phone number, receiving dozens of calls, emails and social media messages daily, according to Hollon. Approximately half the harassing messages have been antisemitic, according to Greenfield.

In the report, Hollon wrote that Engoron was the subject of credible threats before the trial had started, but Trump's Oct. 3 Truth Social post directed at Greenfield exponentially increased the number of threats directed at her.

The report included multiple examples of voicemails that were left on the telephone in Engoron's chambers.

Hollon said the messages have created an "ongoing security risk" for Engoron, his staff and family, but that the gag order had been effective in lowering the number of threats.

"The implementation of the limited gag orders resulted in a decrease in the number of threats, harassment and disparaging messages that the judge and his staff received," Hollon said in the report. "However, when Mr. Trump violated the gag orders, the number of threatening, harassing and disparaging messages increased."

Engoron's lawyer, Lisa Evans, said the threats detailed in Hollon's affirmation justify the gag order, which functions as a reasonable limit on free speech.

"The First Amendment does not prohibit courts from limiting speech that threatens the safety of the court's staff," Evans wrote.

Trump's reply to the filing is due on Nov. 27, after which the First Department will decide whether to fully lift the gag order.