Donald Trump's motorcade has arrived at the New York State Supreme Courthouse in lower Manhattan.

Court is scheduled to get underway at 10 a.m. ET, with Trump scheduled as the day's only witness.

Donald Trump, in New York, had a prep session with his lawyers Sunday ahead his testimony, sources tell ABC News.

Trump's mood during the session fluctuated between fits of anger regarding the case and being "in a good head space," according to sources.

The former president "can be a good witness if he stays focused," one source said.

Former President Trump is due in court to begin his testimony in his $250 million civil fraud trial at 10 a.m. ET.

Hundreds of members of the news media are huddled outside the New York State Supreme Courthouse ahead of Trump's arrival, with some having waited overnight.

After multiple in-court disputes about communications between him and his law clerk, Judge Arthur Engoron modified his limited gag order to cover attorneys in former President Donald Trump's civil fraud trial.

"Defendants may reference my staff as is appropriate to ask about scheduling issues or the management of the trial, which is an integral part of their jobs. What they may not do is to make any further statements about internal and confidential communications (be it conversations, note passing, or anything similar) between me and my staff," Engoron wrote in his supplemental limited gag order on Friday.

Engoron wrote that defense lawyers Chris Kise, Alina Habba, and Clifford Robert made "repeated, inappropriate remarks about my Principal Law Clerk, falsely accusing her of bias against them and of improperly influencing the ongoing bench trial."

The attorneys have raised multiple arguments during the trial that Engoron and his clerk passing notes between each other suggests impropriety and is distracting. Going forward, if the lawyers want to object to communications with his clerk, Engoron advised that they refer to the order as a "blanket statement."

"This gag order is as narrowly tailored as possible to accomplish its purpose, which is to protect the safety of my staff and promote the orderly progression of this trial," Engoron said.

To justify the safety threat, Engoron added that his chambers has received "hundreds of harassing and threatening phone calls, voicemails, emails, letters, and packages" since the start of the trial,

The judge threatened "serious sanctions" for violations of the extended order.

Former President Donald Trump must pay $354 million for fraudulent business practices, Judge Arthur Engoron has ruled.

Trump's sons Donald Trump Jr. and Eric Trump have been fined $4 million apiece, and former Trump Organization CFO Allen Weisselberg has been fined $1 million.

The decision bars Trump barred from serving as an officer of a New York company for three years, and bars his sons for two years apiece.

Regarding the dissolution of Trump's companies, the decision says, "This Court hereby modifies its September 26, 2023, Decision and Order solely to the extent of removing the language ordering the LLCs cancellation en masse. The restructuring and potential dissolution of any LLCs shall be subject to individual review by the Court appointed Independent Director of Compliance in consultation with Judge Jones."

In his decision, Engoron wrote that "Defendants' refusal to admit error -- indeed, to continue it, according to the Independent Monitor -- constrains this Court to conclude that they will engage in it going forward unless judicially restrained."

"Overall, Donald Trump rarely responded to the questions asked, and he frequently interjected long, irrelevant speeches on issues far beyond the scope of the trial," the judge wrote. "His refusal to answer the questions directly, or in some cases, at all, severely compromised his credibility."

"The accountants created these 'compilations' based on data submitted by the Trump entities," the decision said. "In order to borrow more and at lower rates, defendants submitted blatantly false financial data to the accountants, resulting in fraudulent financial statements. When confronted at trial with the statements, defendants' fact and expert witnesses simply denied reality, and defendants failed to accept responsibility or to impose internal controls to prevent future recurrences."

Of Donald Trump Jr., Engoron wrote, "Despite disclaiming responsibility for or knowledge of the Statements of Financial Conditions' contents, Trump, Jr. still insisted that the Statements of Financial Condition were 'materially accurate.'"

Engoron's decision follows an 11-week civil trial in New York, where Trump and three of his adult children testified.

New York Attorney General Letitia James sued Trump, his two adult sons, and Trump Organization executives in September 2022 for issuing fraudulent financial statements -- including over 200 false and misleading asset values between 2011 and 2021 -- to get better loan terms and business deals.