Attacks are heating up in Maine’s Democratic primary for governor ahead of Tuesday’s election, marking a significant change in a race that until recently was largely cordial.

At back-to-back news conferences Thursday, former Maine Senate President Troy Jackson and former Maine Center for Disease Control and Prevention Director Nirav Shah defended their records amid last-minute criticisms from their opponents’ supporters.

“As someone who came up in the snake pit that is Illinois politics, let me just say, we do not want to import those tactics to Maine,” Shah said, referencing his earlier career in Illinois while condemning negativity in the governor’s race. “Nobody wins, we all lose.”

Shah called for an end to a negative attack ad that 314 Action Victory Fund, a political action committee that supports the election of scientists, including Shah, has been running, criticizing Jackson for his record on abortion.

Jackson has refuted the ad, saying at a news conference on Portland’s Western Prom on Thursday that he is a supporter of reproductive rights and the right to abortion.

“I’ve spent the past decade fighting to protect abortion rights,” Jackson said.

Jackson said he “didn’t know anything” about an ad that the Working Families Party, which is supporting Jackson, along with former Maine House Speaker Hannah Pingree and Secretary of State Shenna Bellows, put out last week attacking Shah’s record as director of Illinois’ health department and the groups that have donated to his campaign.

Also attacking Shah Thursday were Illinois state Sen. Cristina Castro, a Democrat, and former Maine Attorney General Mike Carpenter. The two held a virtual media briefing to call attention to Shah’s response to a deadly outbreak of Legionnaires’ disease at the Illinois Veterans’ Home in Quincy in 2015, saying Shah’s response was lacking and he has minimized the seriousness of the outbreak on the campaign trail.

Castro did not say directly whether any of Shah’s four opponents in the primary were involved in organizing the call, saying only that “numerous people” reached out to her about Shah’s time in Illinois and the Legionnaires’ outbreak.

Shah, who has addressed the outbreak numerous times over the last several months, again defended his response, saying, as he has previously, that his agency took the correct scientific approach to the outbreak but could have communicated better about it.

“I have been tested, and as a result of having been tested, I am a better leader for it,” Shah said.

Thursday’s barbs come a little over a week after a poll from the University of New Hampshire Survey Center found Jackson and Shah tied for first place in the Democratic primary, with 28% of likely voters polled selecting each as their first choice.

In addition to Bellows and Pingree, renewable energy entrepreneur Angus King III is also in the race.

Jackson pointed to his rise in the polls as the impetus for the attack ad against him.

“Last week was the polling that showed us tied with (Shah), and all of a sudden the knives have to come out,” he said.

In the Republican primary for governor, seven candidates are running for the chance to continue on to November to face the winner of the Democratic primary, along with independent Rick Bennett, who has also qualified for the general election ballot.

While Democrats have largely been cordial with one another up until recently, Republicans have seen more in-fighting all along. The candidates have largely focused their attacks on Bobby Charles, an attorney and former U.S. assistant secretary of state, who has led polling.

Editor’s note: This story was updated on June 4 to correct the spelling of Sen. Cristina Castro’s name.