AUGUSTA — Widely differing plans to redraw Maine’s congressional district lines emerged today, as Democrats proposed an almost unchanged map while Republicans offered a drastically overhauled configuration of the two districts.

The presentations to the state’s Reapportionment Commission were followed by a testy exchange between the two partisan factions, but in the end both sides promised to work toward a middle ground.

“We certainly are willing to compromise,” said Dan Billings, who represents the Maine Republican Party on the commission and serves as legal counsel to Gov. Paul LePage. “We are not wedded to this map.”

Democrats also agreed to work toward closing the chasm before noon Friday and in advance of a hearing next week to take public testimony on the plans. LePage has called a special legislative session Sept. 27 to vote on a final plan, as required by U.S. District Court.

The Democratic plan leaves Maine’s two existing districts virtually intact, shifting a single town, Vassalboro, from the 1st to 2nd District. Their plan would change the voting district for the central Maine town’s 4,340 people and leave only one county, Kennebec, divided between the two districts, as is now the case.

“In essence, it’s moving one town,” said Sen. Seth Goodall of Richmond, who presented the Democratic plan.

Republicans want to shift the 1st District, which now forms a swath along the southern coastal area, to the western edge of the state, which would shift more than 300,000 people from one district to another and move an incumbent Democratic congresswoman, Chellie Pingree, out of the 1st District she now represents. Maine’s 2nd District is also represented in Congress by a Democrat, Mike Michaud.

While that scenario could cause a runoff between the two incumbents, that’s not a worry to the Democrats, who don’t believe the two would challenge each other. The GOP plan would, however, transfer some towns that have traditionally been loyal to Democrats from the 2nd to 1st District, giving the GOP a little more of an advantage in the 2nd District.

Democrats complained that the GOP plan “disrupts” six counties — Knox, Lincoln, Oxford, Sagadahoc, Androscoggin and Kennebec — by changing their districts, and that it would bring about competing social and political interests in the 1st District by combining rural areas along the western border with the more urbanized areas, including Portland.

“This is a dramatic reshuffling,” said state Sen. Philip Bartlett II of Gorham, a Democratic commission member.

Goodall said the extent of the GOP plan raised questions as to whether the Republicans were negotiating in good faith. His suggestion drew objections from Republican member Rep. Ken Fredette of Newport, who called it “offensive and inappropriate.”

Republicans defended their plan, saying it evens the two districts’ populations almost to a person. They said reapportionment does not have to take into account where a sitting member of Congress lives, or require that new lines be based on where the old district boundaries are.

“Our argument is there is no such thing as a traditional district in the state of Maine,” the GOP’s John Tardy told fellow commissioners. “One person, one vote, is the fundamental federal law of the land, and that’s where we should be focused.”

Billings dismissed the Democratic contention that 360,000 people would be shifted from one district to another, saying, “No one’s moving here. We’re simply changing a line on a map.”

The panel’s chairman, Michael Friedman, repeatedly asked members to not debate their plans and limit their comments to fact-finding. Friedman, an independent, also urged the two sides to narrow their differences so a unified plan can be reviewed by the public next Tuesday.

“This is not an impossible task,” said Friedman.

Several other states, including Georgia, Maryland, Rhode Island, South Dakota and North Dakota, also have special sessions scheduled to take up redistricting.