On his way into the courtroom for the day's proceedings, Trump once again alleged that the trial constitutes election interference, claiming that the proceedings are unfairly keeping him off the campaign trail.

"Everybody knows that I'm here instead of being able to be in Pennsylvania and Georgia and lots of other places campaigning, and it's very unfair," he told reporters.

"It's a very, very sad day in America," he said. "I can tell you that."

The former president is seated at the defense table between his lawyers Todd Blanche and Emil Bove.

-Mike Pappano

The proceedings are underway in former President Donald Trump's hush money trial. Trump and Manhattan District Attorney Alvin Bragg are both in the courtroom.

Three prosecutors -- Joshua Steinglass, Matthew Colangelo, and Susan Hoffinger -- are seated at the counsel table.

Bragg is seated in the front row of the gallery with approximately a dozen lawyers and staff from his office.

The first witness prosecutors with the Manhattan DA's office plan to call is former National Enquirer publisher David Pecker, according to two sources familiar with the matter.

ABC News previously reported that prosecutors planned to call Pecker as a witness, but sources now say he's expected to be the first witness to take the stand.

Pecker served as the longtime chief executive of American Media Inc., which published the National Enquirer.

Shortly after Trump announced his 2016 presidential campaign, Pecker met with Trump and agreed to act as the "eyes and ears" of the campaign by looking out for and killing negative stories about Trump, according to the Manhattan DA.

As part of the arrangement, Pecker allegedly directed a deal to pay $30,000 to a former Trump Tower doorman regarding the false allegation that Trump allegedly fathered a child out of wedlock, prosecutors say. Then-Trump attorney Michael Cohen allegedly insisted that the deal stay in place even after AMI discovered the allegation was false, and AMI paid the doorman, according to the Manhattan DA.

-Katherine Faulders

After a week-long selection process, the jurors in Donald Trump's New York hush money case are scheduled to hear opening statements this morning in the first criminal trial of a former U.S. president.

To prove their case, lawyers for Manhattan District Attorney Alvin Bragg need to convince twelve jurors beyond a reasonable doubt that Trump repeatedly falsified records to unlawfully influence the 2016 presidential election.

"This case has nothing to do with your personal politics or your feelings about a particular political issue," prosecutor Joshua Steinglass told prospective jurors on Thursday. "It's not a referendum on the Trump presidency, a popularity contest, or any indication of who you plan to vote for this fall. This case is about whether this man broke the law."

Trump's lawyers are expected to focus their efforts on going after the credibility of prosecution witnesses, suggesting the case itself is politically motivated and arguing that the former president never intended to commit a crime.

When the National Enquirer's parent company AMI signed a non-prosecution agreement with federal prosecutors in New York in September 2018, AMI was negotiating to sell the Enquirer and two other tabloids to Hudson News Group for $100 million, former publisher David Pecker testified under cross-examination.

Defense attorney Emil Bove suggested the pending sale put Pecker under pressure to resolve a federal campaign finance investigation over its payment to quash stories damaging to Donald Trump's presidential ambitions.

"You knew to finalize that deal, to consummate it, you had to clear out the investigations?" Bove asked.

"Yes," Pecker responded. "From a timing standpoint it would have added stress to the transaction."

On Thursday Pecker testified he had been "very worried" about the investigation. He had received a letter from the Federal Election Commission and said he called up Michael Cohen. "I said 'I'm very worried,'" he testified.

Pecker said Cohen responded, "Why are you worried? Jeff Sessions is the Attorney General and Donald Trump has him in his pocket."

The defense appears to be suggesting AMI cooperated with federal campaign finance investigations not because the company had done anything wrong related to the 2016 Trump campaign, but out of financial considerations in order to preserve the $100 million deal with Hudson News, which was finalized in April 2019.