Donald Trump returns to the hush money trial Tuesday facing a threat of jail time for additional gag order violations as prosecutors gear up to summon big-name witnesses including porn actor Stormy Daniels.

An attorney for Daniels, Clark Brewster, told The Associated Press that the porn actor, whose real name is Stephanie Clifford, is “likely” to be called as a witness in the trial on Tuesday.

Trump said earlier Tuesday that he was “recently told” who the witness would be on Tuesday and complained he should've been given more notice.

In the final weeks of Trump's 2016 Republican presidential campaign, his then-lawyer and personal fixer, Michael Cohen, paid Daniels USD 130,000 to keep quiet about what she says was an awkward and unexpected sexual encounter with Trump at a celebrity golf outing in Lake Tahoe in July 2006. Trump denies having sex with Daniels.

Trump and his campaign were reeling from the October 7, 2016, publication of the never-before-seen 2005 “Access Hollywood” footage in which he boasted about grabbing women's genitals.

He spoke with Cohen and Hope Hicks, his campaign's press secretary, by phone the next day as they sought to limit damage from the tape and keep his alleged affairs out of the press.

Cohen paid Daniels after her lawyer at the time, Keith Davidson, indicated she was willing to make on-the-record statements to the National Enquirer or on television confirming a sexual encounter with Trump.

National Enquirer editor Dylan Howard alerted Pecker and then, at Pecker's direction, told Cohen that Daniels was agitating to go public with her claims, prosecutors said. Daniels had previously sought to sell her story to another celebrity gossip magazine, Life & Style, in 2011.

The jury on Monday heard from two witnesses, including a former Trump Organization controller, who provided a mechanical but vital recitation of how the company reimbursed payments that were allegedly meant to suppress embarrassing stories from surfacing and then logged them as legal expenses in a manner that Manhattan prosecutors say broke the law.

The testimony from Jeffrey McConney yielded an important building block for prosecutors trying to pull back the curtain on what they say was a corporate records cover-up of transactions designed to protect Trump's Republican presidential bid during a pivotal stretch of the race.

It focused on a USD 130,000 payment from Cohen to Daniels and the subsequent reimbursement Cohen received.

McConney and another witness testified that the reimbursement checks were drawn from Trump's personal account. Yet even as jurors witnessed the checks and other documentary evidence, prosecutors did not elicit testimony Monday showing that Trump dictated that the payments would be logged as legal expenses, a designation that prosecutors contend was intentionally deceptive.

McConney acknowledged during cross-examination that Trump never asked him to log the reimbursements as legal expenses or discussed the matter with him at all.

Another witness, Deborah Tarasoff, a Trump Organization accounts payable supervisor, said under questioning that she did not get permission to cut the checks in question from Trump himself.

“You never had any reason to believe that President Trump was hiding anything or anything like that?” Trump attorney Todd Blanche asked.

”Correct,” Tarasoff replied.

The testimony followed a stern warning from Judge Juan M. Merchan that additional violations of a gag order barring Trump from inflammatory out-of-court comments about witnesses, jurors and others closely connected to the case could result in jail time.

The USD 1,000 fine imposed Monday marks the second time since the trial began last month that Trump has been sanctioned for violating the gag order. He was fined USD 9,000 last week, USD 1,000 for each of nine violations.

“It appears that the USD 1,000 fines are not serving as a deterrent. Therefore going forward, this court will have to consider a jail sanction,” Merchan said before jurors were brought into the courtroom.

Trump's statements, the judge added, “threaten to interfere with the fair administration of justice and constitute a direct attack on the rule of law. I cannot allow that to continue.”

Trump sat forward in his seat, glowering at the judge as he handed down the ruling. When the judge finished speaking, Trump shook his head twice and crossed his arms.

Yet even as Merchan warned of jail time in his most pointed and direct admonition, he also made clear his reservations about a step that he described as a “last resort.”

“The last thing I want to do is put you in jail,” Merchan said. “You are the former president of the United States and possibly the next president as well. There are many reasons why incarceration is truly a last resort for me. To take that step would be disruptive to these proceedings.”

The latest violation stems from an April 22 interview with television channel Real America's Voice in which Trump criticized the speed at which the jury was picked and claimed, without evidence, that it was stacked with Democrats.

Prosecutors are continuing to build toward their star witness, Cohen, who pleaded guilty to federal charges related to the hush money payments. He is expected to undergo a bruising cross-examination from defense attorneys seeking to undermine his credibility with jurors.

Trump, the Republican Party's presumptive presidential nominee, is charged with 34 felony counts of falsifying business records in connection with the hush money payments but has pleaded not guilty and denied any wrongdoing. The trial, the first of his four criminal cases to come before a jury, is expected to last another month or more.