A new independent poll shows two-term Gov. Janet Mills with a 10-point lead over combat veteran and oyster farmer Graham Platner in the Democratic U.S. Senate primary race.

The survey of 318 likely Democratic primary voters released Wednesday by Portland-based Pan Atlantic Research shows Mills with 47% support, compared to 37% for Platner and 14% undecided. The margin of error was 6.2% in the primary survey.

The poll, conducted between Nov. 29 and Dec. 7, highlights an unsettled primary battle.

The Platner campaign has touted polls from outside groups showing him with a lead, while the Mills campaign has highlighted a poll showing Platner losing support after voters are told about his old internet posts and tattoo of a Nazi image that’s since been covered.

The Pan Atlantic poll has Mills, 77, leading Platner 54% to 23% in the more conservative, rural 2nd Congressional District, while Platner, 41, leads Mills in the more liberal 1st District, 45% to 43%.

Mills’ strongest demographic is voters aged 55 or older, while Platner, the political newcomer, leads among voters 18-54.

Both are in a statistical dead heat with Republican Sen. Susan Collins, who is seeking her sixth term, though Platner polls slightly better — 43% to 42%, over Collins, compared with Mills, who was tied at 43%. About 15% of respondents were undecided.

Mills is more popular than Collins, though both are underwater in terms of favorability. Mills’ rating is -8, while Collins is -17, only two points better than President Donald Trump. Platner’s rating was not tested.

The poll, which misspelled Platner’s name, determined likely voters based on whether they said they were likely, very likely or certain to vote next year. The firm partnered with the market research company Dynata to recruit a random sample of 1,075 Mainers online, garnering 820 responses for the full survey. The full survey’s margin of error was 3.7%.

The poll has warning signs for Mills, notably that 48% of people said the state is on the wrong track. That’s up from 41% in May and the highest mark in the last three years.

People were also asked about key issues facing the state, with 68% identifying cost of living/inflation, 41% saying health care, 37% homelessness, 33% high taxes and 23% immigration.

It also asked whether Maine should comply with federal demands to change the state’s transgender athlete policies, with 45% agreeing that Maine’s policies should be changed, 36% opposed and 19% neutral.