“To take that step would be disruptive to these proceedings,” he said.

Trump did not reply to Merchan’s warning.

Merchan, a stern but soft-spoken judge, did not raise his voice even as he spoke about a once-unthinkable scenario – the presumptive Republican nominee for president running for office from a jail cell. Trump is the first former US president to face a criminal trial, and Merchan’s toughest warning to date came on the fourth week of the proceedings, at roughly the halfway mark of the trial.

In his ruling, Merchan decided that Trump’s comments in an interview – in which he criticised the make-up and selection of his jury – had violated the gag order, while three other public statements he made around that same period in late April had not.

Merchan’s decision marks the second time Trump has been told his statements outside court – whether in interviews or social media posts – violated the court order.

While Trump has tangled with judges in past civil trials, the stakes in a criminal trial are higher because the threat of incarceration hangs over the entire process. Outside the courtroom, Trump has said he was willing to go to jail to defend what he calls his constitutional right to speak as a presidential candidate.

At the end of the court session, Trump told reporters outside the courtroom that the trial was a disgrace, and “even more disgraceful is the gag order where, basically, I have to watch every word I tell you people”.

Trump suggested he was, in fact, willing to go to jail in the stand-off with the judge. “Our Constitution is much more important than jail. It’s not even close. I’ll do that sacrifice any day,” he said.

His lawyers have argued that Trump has to be able to respond to the verbal attacks of his political rivals and critics, particularly when that criticism was levelled by a witness against him.

The 12th day of Trump’s trial in New York, on charges of falsifying business records to hide hush money payments to adult film actress Stormy Daniels, was otherwise consumed by the dry but factually critical details about the checks Trump signed in 2017.

Loading

Witnesses confirmed they handled the paperwork that helped pay former Trump lawyer Michael Cohen for what prosecutors say was a corrupt scheme to influence the election by keeping the actress silent during the 2016 presidential campaign about her alleged tryst with Trump years earlier.

Trump has pleaded not guilty to the 34 counts and denied any such sexual encounter with Daniels, whose real name is Stephanie Clifford.

To try to prove their case, prosecutors called Jeffrey McConney, a former senior accountant at the Trump Organisation, to describe how he was instructed to arrange the payments to Cohen.

McConney said he was summoned by his boss, chief financial officer Allen Weisselberg, in January 2017 to discuss the issue.

“Allen said we had to get some money to Michael or reimburse Michael,” McConney testified. “He tossed a pad towards me and I started taking notes about what Allen said.” Prosecutors say the money was meant to pay Cohen back for paying Daniels $US130,000 in October 2016 to keep quiet.

Loading

The Trump Organisation added money on top of that to include a bonus, and reimbursement for a separate $US50,000 business expense Cohen said he paid on Trump’s behalf, McConney said. They also added to the amount so that Cohen wouldn’t lose money on the transactions because of the taxes he would have to pay.

“We added everything up, and we came up with the amount we wanted to pay him,” which was $US420,000, said McConney. That figure was based, according to an exhibit introduced as court evidence, partly on a $US130,000 payment from Essential Consultants LLC, a company Cohen created, which paid Daniels.

McConney’s testimony is important to the prosecution case because his former boss, Weisselberg, is unlikely to testify after having previously pleaded guilty to perjury in a different case.

While McConney was helpful to prosecutors in confirming the general purpose of the payments and that most of the checks were signed by Trump from his personal account, McConney conceded there were important details he didn’t know.

Prosecutors say reimbursing Cohen for the payment made to Daniels was wrongly categorised in company books as legal costs, when it should have been noted as a campaign expenditure.

Jurors listened as McConney and a former subordinate described monthly emails from Cohen in 2017 meant to serve as invoices for his payment.

While McConney’s testimony helped prosecutors, he was one of several witnesses so far who seem to remain on good terms with Trump even after testifying against him.

McConney, who retired after about 36 years working at the Trump Organisation, stepped off the witness stand around midday, and as he walked out of the courtroom, Trump grinned at him and pumped his fist.

When the next witness, Trump Organisation bookkeeper Deborah Tarasoff, left the stand, she smiled at Trump’s son, Eric Trump, sitting behind him in court.

The Washington Post

Get a note directly from our foreign correspondents on what’s making headlines around the world. Sign up for our weekly What in the World newsletter.