Democratic U.S. Senate candidate Graham Platner holds a slim lead within the margin of error over incumbent Republican candidate Susan Collins, a new poll shows on Monday.

The poll comes as his campaign faces mounting scrutiny amid allegations from some of his former romantic partners, reported by The New York Times.

The 41-year-old Marine Corps veteran—running against David Costello in the Maine primary on Tuesday to determine who faces Collins in the general election—has denied allegations involving physicality, saying the accusations are "simply not true" and describing them as politically motivated.

Newsweek reached out to both Platner and Collins via email for comment Monday night.

What To Know

According to the poll from Tavern Research, Collins has 49 percent compared to Platner's 51 percent. The poll was taken from June 5 to June 8 among 1,642 Maine respondents, with a margin of error of 2.8 percent.

In a generic poll, Collins loses to a Democratic candidate 45 percent to 55 percent, the survey shows.

Platner's favorability in the poll is 42 percent compared to a 51 percent unfavorable rating. Collins' favorability rating is 41 percent compared to a 57 percent unfavorable rating.

Last week, one former girlfriend of Platner's, Lyndsey Fifield, alleged that Platner had engaged in physically threatening behavior during their relationship over a decade ago, claims that have sparked questions about the Democratic Senate candidate's past.

In one instance, Fifield alleged that Platner twisted her arm behind her back during an argument, shoved her into a bedroom and blocked her from exiting. She says she fell asleep and then left the next morning, the Times reports. “It hurt,” Fifield said, adding that “It didn’t cause an injury, it didn’t break my arm.”

Fifield also told the outlet that Platner "never hit me, he never punched me.” The Times said it could not independently corroborate the incidents alleged by Fifield.

After the article's publication, Fifield criticized the Times on social media in lengthy posts, questioning how her account was represented and that important context had been omitted.

A spokesperson for the Times told Newsweek: "We published accounts provided by several women who were in romantic relationships with Graham Platner. Our story accurately presents each of these accounts as told to our reporters and according to our standards. We stand by our reporting of the accounts from Ms. Fifield and the other women, who provided a revealing look at the behavior of a major candidate for the U.S. Senate."

At a campaign rally in Bar Harbor, Maine, on Friday, Platner thanked his supporters for standing by him amid the scrutiny. "Maine, you had my back," Platner told the cheering crowd. “When hurtful things I said on the internet a decade ago came out into the public, as I shared my personal journey through PTSD [post-traumatic stress disorder] and darkness of recovery, and accountability and growth, Maine had my back."

“And when politically motivated, serious and false accusations are made against me, Maine, you have my back,” Platner later added.

What Other Polls Show

A new Public Policy Polling survey found Platner ahead of Collins by 4 points. The poll surveyed 670 registered Maine voters and found the Democrat up 49 percent to Collins’ 45 percent, with 6 percent undecided.

The survey was conducted on June 2 and June 3—after allegations of sexually explicit messages sent by Platner were reported—and has a margin of error of 3.8 percent. In an aggregate of polling for the race by the Times, it is noted that the poll was sponsored by Platner.

In a Pine Tree State Poll conducted by the University of New Hampshire Survey Center, Platner led Collins 51 percent to 42 percent. The poll showed that 2 percent said another candidate and 6 percent didn't know. It was taken from May 21 to May 25 among 1,280 likely general-election voters, with a margin of error of 2.7 percent. Allegations of sexually explicit messages sent by Platner were reported after this poll was released.