AUGUSTA — A poll released Wednesday shows Gov. Janet Mills 10 percentage points ahead of fellow Democrat Graham Platner in the U.S. Senate primary.

Among likely primary voters, Mills leads 47% to 37%, according to the 67th Pan Atlantic Research Omnibus Poll. That leaves 13% undecided.

The poll gathered answers from 820 likely voters and has a margin of error of 3.7%.

When broken down by district, Mills leads Platner 54% to 23% in the more conservative 2nd Congressional District, while Platner narrowly leads Mills 45% to 43% in the 1st District.

Mills, 77, a two-term governor, entered the race just about two months ago, following Platner, 41, a Sullivan oyster farmer who announced his run in August.

Both are hoping to win the June Democratic primary and the right to face U.S. Susan Collins, a 73-year-old five-term Republican, in November.

Regardless of which candidate wins the Democratic primary, it looks to be a tough matchup with Collins. The poll shows a 43% to 43% tie in a race between Mills and Collins, with 14% undecided.

Poll results favored Platner over Collins, but only by 1 percentage point. In that theoretical matchup, Platner earned 43% to Collins at 42% with 15% undecided.

The Pan Atlantic poll is quite different from results released in October from the University of New Hampshire. In that poll, Platner had 58% support over Mills, who was at only 24%.

At the time, pollster Andrew Smith said he did not believe that survey respondents had had time to digest several news stories that described Platner’s old social media posts that were critical of rural Americans and those that appeared to dismiss military sexual assaults. 

Platner has apologized, saying many of the comments came shortly after he left the military when he was suffering from PTSD and depression.

The poll released this week by Pan Atlantic also asked respondents about the key issues facing Maine, with 68% naming the cost of living and inflation as their top concern. Next on the list is healthcare access and affordability (41%), followed by housing and homelessness at 37%.