A veteran tabloid publisher told a court in New York on Tuesday that he pledged to be Donald Trump’s “eyes and ears” during his 2016 presidential campaign.

David Pecker recounted how he promised the then-candidate that he would help suppress stories that had the potential to harm the Republican’s election bid.

The evidence from Mr Pecker was designed to bolster prosecutors’ assertions of a decades-long friendship between Trump and the former publisher of the National Enquirer that culminated in an agreement to give the candidate a heads-up on negative tips and stories so they could be quashed.

Mr Pecker is the first witness in Trump’s historic hush money trial in Manhattan, where he faces 34 felony counts of falsifying business records in connection with payments meant to prevent harmful stories from surfacing during the final days of the 2016 campaign.

The stories included an adult film actor’s claims of an extramarital sexual encounter a decade earlier.

The effort to suppress unflattering information was designed to influence the election, prosecutors have alleged in seeking to elevate the gravity of the first trial of a former American president.

Mr Pecker described for jurors a pivotal August 2015 meeting at Trump Tower involving Trump, his lawyer and personal fixer Michael Cohen, and another aide, Hope Hicks, in which he was asked what he and the magazines he led could do for the campaign.

Mr Pecker said he volunteered to publish positive stories about Trump and negative stories about his opponents. But that was not all, he said, telling jurors how he told Trump: “I will be your eyes and ears.”

“I said that anything I hear in the marketplace, if I hear anything negative about yourself, or if I hear about women selling stories, I would notify Michael Cohen,” so that the rights could be purchased and the stories could be killed.

“So they would not get published?” prosecutor Joshua Steinglass asked.

“So they would not get published,” Mr Pecker replied.

Mr Pecker’s resumption of evidence on Tuesday followed a hearing earlier in the day in which prosecutors urged Judge Juan Merchan to hold Trump in contempt and fine him 1,000 dollars for each of 10 social media posts that they say violated an earlier gag order barring attacks on witnesses, jurors and others involved in the case.

Judge Merchan did not immediately rule, but he appeared sceptical of a defence lawyer’s arguments that Trump was merely responding in his posts to others’ attacks and had been trying to comply with the order.

Mr Pecker’s testimony began on Monday after opening statements that offered the 12-person jury — and the voting public — radically divergent roadmaps for a case that will unfold against the backdrop of a closely contested White House race in which Trump is not only the presumptive Republican nominee but also a criminal defendant facing the prospect of a felony conviction and prison.

Prosecutors allege that Trump sought to illegally influence the 2016 race through a practice known in the tabloid industry as “catch-and-kill” — catching a potentially damaging story by buying the rights to it and then killing it through agreements that prevent the paid person from telling the story to anyone else.

In this case, that included a 130,000-dollar (£105,000) payment to adult film actor Stormy Daniels to silence her claims of an extramarital sexual encounter that Trump denies.

Trump faces 34 felony counts of falsifying business records — a charge punishable by up to four years in prison. He has repeatedly denied any wrongdoing.