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.

Donald Trump has lost his appeal to throw out the limited gag orders and associated fines in his civil fraud trial.

In a decision Thursday, New York's Appellate Division, First Department rejected Trump's request to annul and vacate the limited gag orders imposed by Judge Arthur Engoron that prohibit Trump and attorneys from commenting on the judge's staff.

In November, Trump's lawyers asked the Appellate Division to vacate the gag orders, citing a provision of New York state law to personally sue Judge Engoron. But the court said in today's ruling that the method used to appeal the gag orders was an improper application of the law.

"To the extent there may have been appealable issues with respect to any of the procedures the court implemented in imposing the financial sanctions, the proper method of review would be to move to vacate the Contempt Orders, and then to take an appeal from the denial of those motions," the ruling said, indicating that Trump should use the normal appellate process to pursue the vacating of the gag orders.

The court also determined that the "extraordinary remedy" requested by Trump's lawyers did not match the minimal potential harm from barring statements about Engoron's staff.

"Here, the gravity of potential harm is small, given that the Gag Order is narrow, limited to prohibiting solely statements regarding the court's staff," the decision said.