Bloomberg's former mayoral opponent to file FEC complaint against Bloomberg News

Mike Bloomberg is being visited by the specter of campaigns past.

Mark Green, Bloomberg's Democratic opponent in the 2001 NYC mayoral race, is announcing that this week, he will file an official complaint with the Federal Election Commission against Bloomberg News for "illegal corporate in-kind contributions" to the billionaire former mayor of New York's presidential campaign.

Green, who served from 1994 through 2001 as New York City’s first public advocate, was, at the time of his mayoral run, the prohibitive favorite of what unexpectedly became one of the more narrow elections in recent memory. Green ultimately lost to Bloomberg by a small margin.

Green's complaint now alleges that Bloomberg News is proffering biased coverage of the 2020 primary - putting out negative stories on Bloomberg's opponents while avoiding scrutiny of their eponymous candidate.

Green alleges in the complaint he will file that Bloomberg News' coverage is a "coordinated contribution by a corporation to a candidate."

Green points to the memo that went out to the Newsroom staff after Bloomberg announced his bid for the Democratic nomination - saying that the outlet would maintain its "tradition" of not investigating Bloomberg, his family or foundation, and that in the interest of fairness it would "extend the same policy to his rivals in the Democratic primaries."

His allegation of coordination rests on the perspective that Bloomberg News is not providing fair and balanced coverage of the 2020 primary as behooving Bloomberg. In an interview with ABC News, Green outlined his proof as "admittedly, a content analysis of their coverage, which is one-sided."

He likens Bloomberg News as tantamount to a personal PAC for Bloomberg's campaign.

"It's not money - Mike doesn't need money," Green said, adding it's more the lack of inquiry that serves Bloomberg. "The point is not that Mike is corrupt - but that the process might be," he said.

In response to ABC News's request for comment, a Bloomberg News spokesperson said "Our coverage speaks for itself."

The Bloomberg presidential campaign declined to comment.

In a memo to newsroom staff sent the same day Bloomberg announced his presidential candidacy, John Micklethwait, Bloomberg News' editor-in-chief, sought to make clear how the news organization would handle coverage.

"We cannot treat Mike's Democratic competitors differently from him. If other credible journalistic institutions publish investigative work on Mike or the other Democratic candidates, we will either publish those articles in full, or summarize them for our readers - and we will not hide them, "the memo read. "For the moment, our P&I team will continue to investigate the Trump administration, as the government of the day. If Mike is chosen as the Democratic presidential candidate (and Donald Trump emerges as the Republican one), we will reassess how we do that."

Though Green says the "in-kind" issue his complaint outlines is not about money - Green told ABC that it feels like déjà vu all over again from his 2001 run against Bloomberg - when Bloomberg also poured enormous sums from his personal fortune into the race: $74 million in total.

"It feels like oh here we go all over again - like are you kidding?" Green told ABC.

"He's trying to do in this run for president what he did for mayor: he's trying to buy it, 'fair and square," Green said, clarifying that he meant that last quip as tongue-and-cheek.

The subjective nature of Green's complaint may blunt the impact it could have: news coverage is not the typical kind of corporate in-kind contribution investigated by the FEC; it looks more primarily at campaign finance violations, issuing fines and guidance to campaigns about adhering to election law. Moreover -- the FEC does not currently have a quorum: four commissioners are required to authorize an investigation; there are currently three.

With Bloomberg's unorthodox run for the White House, however, comes a unique situation: most candidates don't own media companies. Thus what might be considered as an "in-kind" "coordinated contribution" takes on fresh nuance.

Green says that he's concerned "there need to be more bright line tests" in FEC regulations.

"We are getting close to a system where only billionaires need apply."

Dovetailing with the populist tone he takes towards the electoral system, Green tells ABC he supports Massachusetts Sen.Elizabeth Warren's candidacy; Warren has built her bid for the Democratic nomination on denouncing big money in politics.

Green said he is not working in coordination with the Warren campaign.

Asked to confirm this, the Warren campaign declined to comment.

On Thursday, Green said he has spoken with Warren and the campaign over the past two years as part of his support for her but he had not specifically spoken with her about the FEC complaint before he sent it.

Bloomberg and Green have a decades' long history.

Their nail-biter bid for Gracie Mansion in 2001 took a bitter turn towards the end: in the contest's final 24-hour stretch, Green's campaign put out a negative TV ad on Bloomberg based on the sexual harassment suit filed against Bloomberg alleging that he told a pregnant female employee to "Kill it."

The ad seized on the explosive allegation at the time and underscored that the purported remarks might make New Yorkers rethink supporting Bloomberg.

The New York Times reported at the time that Bloomberg responded to the ad saying that Green "has no shame and is absolutely desperate."

ABC News asked Green if there was any lingering animus between Bloomberg and himself: Green said no.

"Am I upset about a race from 19 years ago?" Green told ABC. "My goodness, there's a statute of limitations on election results, and a statute of limitations on being a sore loser."

"In fact, Mike and I like each other. We get along, personally," Green continued. "Whatever motivation some critic might attribute is irrelevant to whether {Bloomberg} has violated FEC law."

Green added that after Bloomberg beat him in 2001, after calling to congratulate him first, Green called two days later and apologized for running the "Kill it" ad.

"I didn't want to run it - then after being carpet-bombed by his negative ads, I felt like I had to," Green said, adding that Bloomberg accepted his apology, but didn't want to continue that conversation.

ABC News' Tonya Simpson contributed to this report.