Donald Trump’s lawyer has been warned he is “losing all credibility” as a judge considered whether to punish the former president for violating a court gag order.

Prosectors asked Justice Juan Merchan to punish Trump for violating the order which prevents him from publicly criticising witnesses and jurors involved in the historic criminal hush money trial.

However Trump’s defence lawyer Todd Blanche argued that Trump was responding to “political attacks” and should not be punished.

At a hearing to consider the issue, Justice Merchan appeared to grow frustrated after Trump’s team did not provide specific examples of the attacks to which Trump was said to be responding.

“You’ve presented nothing,” Merchan said to Blanche.

“I’ve asked you eight or nine times, show me the exact post he was responding to. You’ve not even been able to do that once.

“Mr Blanche, you’re losing all credibility. I have to tell you right now, you’re losing all credibility with the court.”

The judge’s gag order prevents Trump from publicly criticising witnesses, court officials and their relatives. Trump has said it is a violation of his constitutional free speech rights.

New York prosecutor Christopher Conroy said Trump has run afoul of the order with posts on his Truth Social platform.

“Defendant has violated this order repeatedly and hasn’t stopped,” Conroy told Merchan.

“The court should now hold him in contempt.”

Conroy pointed to an April 10 post that called porn star Stormy Daniels and his former lawyer Michael Cohen “sleazebags.”

Both are expected to testify in the first criminal trial of a former US president. Conroy said other posts led to media coverage that prompted a juror last week to withdraw over privacy concerns.

“He knows what he’s not allowed to do and he does it anyway,” Conroy said of Trump.

“His disobedience of the order is wilful. It’s intentional.”

The $US10,000 fine ($15,415) sought by Conroy would be a relatively small penalty for Trump, who has posted $US266.6 million ($411.0 million) in bonds as he appeals civil judgements in two other cases.

Conroy said he was not at this point asking Merchan to send Trump to jail for up to 30 days, as New York law allows.

“The defendant seems to be angling for that,” Conroy said.

Blanche said his posts were responses to political attacks by Cohen and not related to his former lawyer’s expected testimony.

“He’s allowed to respond to political attacks,” Blanche said.

Outside court, Trump falsely claimed the gag order prevented him from defending himself.

“I’d love to say everything on my mind but I’m restricted because of a gag order,” Trump said.

‘Buying silence’

Trump was charged by Manhattan District Attorney Alvin Bragg with falsifying business records to cover up a $US130,000 ($200,398) payment shortly before the 2016 US election to buy the silence of Daniels about a sexual encounter she has said they had in 2006. Trump has pleaded not guilty and denies such an encounter took place.

Prosecutors have said it was part of a wider conspiracy to hide unflattering information from voters at a time when he was facing multiple accusations of sexual misbehaviour.

In his opening statement on Monday, defence lawyer Todd Blanche said Trump did not commit any crimes. Blanche said Trump acted to protect his family and his reputation and accused Daniels of trying to profit from false accusations.

On Tuesday, jurors are expected to hear more testimony from former National Enquirer publisher David Pecker, who prosecutors say participated in a “catch and kill” scheme to suppress unflattering stories about Trump and help him get elected.

Pecker, 72, testified on Monday that his company paid for stories – an unusual practice in journalism.

Trump has said the payments were personal and did not violate election law.

The case may be the only one of the Republican Trump’s four criminal prosecutions to go to trial before his November 5 election rematch with Democratic President Joe Biden.

A guilty verdict would not bar Trump from taking office but it could hurt his candidacy. Reuters/Ipsos polling shows that half of independent voters and one in four Republicans say they would not vote for Trump if he is convicted of a crime.

-with AAP