PORTLAND — A new poll on the race for Maine governor suggests Republican Gov. Paul LePage has a significant lead over the Democratic nominee, U.S. Rep. Mike Michaud, while independent candidate Eliot Cutler has nearly 20 percent support.

But the poll released Thursday by the Portland-based Pan Atlantic SMS, which surveyed 400 Maine residents in the final week of September, also suggests that if the race were between LePage and Michaud, it would be a statistical dead heat.

Including “leaning” voters, LePage leads the race with 39.3 percent, followed by Michaud with 33.6 percent and Cutler with 19.5 percent. The poll suggests about 7.8 percent of voters were undecided.

Pan Atlantic has regularly shown stronger support for Cutler than most other polling firms, but if the results are accurate, they reflect a surge in support for Cutler — compared to a range of results from other polling firms in recent months that have had Cutler in the low teens — that he has been counting on throughout his campaign.

However, Cutler’s support has actually dropped a point since a Pan Atlantic poll in April and is on par with where the independent has polled with Pan Atlantic since November 2013.

The campaigns of Cutler and Michaud were quick to react, alternately praising the poll and dismissing it.

Cutler’s campaign manager Ted O’Meara issued a memo noting the poll was in line with the campaign’s own internal polls released in late September.

“Despite every conceivable advantage — no primary, millions from special interests, and a total makeover on issues from choice to equal rights to background checks — Michael Michaud, just like Libby Mitchell in 2010, can’t win an election against Paul LePage,” O’Meara said in a prepared statement.  

It’s a narrative Cutler’s campaign has been repeating in recent weeks, with Cutler’s campaign spokeswoman Crystal Canney saying polling suggests, “Michaud can’t close the deal with Maine voters.”

But Michaud’s campaign spokeswoman, Lizzy Reinholt, said the data in the poll were more than 10 days old and not reflective of the current conditions in the race.

Michaud’s camp released its latest internal poll which was concluded Wednesday. Reinholt said regardless, the overall trend of all polling so far suggests the same story, that LePage and Michaud are in a tight race, while Cutler is bringing up the rear.

The Pan Atlantic results varied significantly from a new CBS/New York Times poll released Thursday, which suggests Michaud maintains a narrow lead over LePage with Cutler far behind.

That poll, which sampled more than 1,500 voters between Sept. 20 and Oct. 1, found 37 percent support for Michaud, 35 percent for LePage and 10 percent for Cutler. About 13 percent of respondents said they still weren’t sure who they would vote for on Election Day, and a significant number of the decided said they could change their minds.

The SMS-Pan Atlantic Group was heralded for producing the most accurate polling results in 2010 when it was the polling firm to most closely predict the outcome of a three-way race among LePage, Cutler and Democratic State Senate President Libby Mitchell.

A poll the agency released in mid-October that year suggested Cutler was trailing with only 14 percent to Mitchell at 28 percent and LePage at 32 percent.

Another poll by the company released in late October suggested Cutler had surged to 30 percent and LePage was polling at 38 percent, with 21 percent for Mitchell.

LePage won the race with 38.3 percent of the vote with Cutler finishing second with 36.5 percent and Mitchell with 19 percent.

The race in 2010 included two other independent candidates, Shawn Moody and Kevin Scott, who fetched 5 percent and 1 percent of the vote, respectively.