AUGUSTA, Maine — In their latest attempts at compromise, Maine Democrats and Republicans serving on the state’s congressional redistricting commission released new maps on Monday, one day ahead of their final meeting.

The Democrats’ new plan addresses Republicans’ main concern about making sure the population deviation between Maine’s two districts is virtually equal.

The “Vassalboro-Gardiner plan” shifts the towns of Gardiner, Vassalboro, Vienna, Rome, Oakland, Wayne and Unity Township in order to achieve the population deviation of one. The plan would affect nearly 20,000 voters but splits only Kennebec County, which already is divided between the 1st and 2nd Districts.

“The Republicans told us their top priority was to bring the population difference between the districts down to one,” said Sen. Seth Goodall of Richmond, the Democrats’ lead negotiator. “Our top priority has consistently been to provide the least disruptive proposal. We believe our new map addresses both of these priorities and strikes a fair and simple balance.”

Republicans, meanwhile, released their latest map. It shifts Androsoggin County from the 2nd District to the 1st but keeps the coastal counties of Lincoln, Sagadahoc and Knox — including U.S. Rep. Chellie Pingree’s hometown of North Haven — in the 1st District.

“Throughout this process, Republicans have attempted to accommodate their Democratic counterparts on the commission, only to have them move the goalposts again and again,” said Rep. Less Fossell, R-Alna. “We feel this latest consensus map is a reasonable proposal, and we hope that they will embrace the spirit of compromise and put the people of Maine over their political agenda.”

Both sides said they are frustrated with a lack of compromise, but neither has worked on a plan together. Instead, the parties are adapting their own ideas and hoping the other side relents.

Democrats said Monday the new GOP plan is slightly better than the first plan, but is still radical.

“So far the Republicans have submitted two radical maps and a secret one,” said Rep. John Martin, D-Eagle Lake. “They keep talking about their efforts to compromise, but they won’t share their maps with the public or have a sincere negotiation. Instead, their approach has been ‘take it or leave it’ — that’s not compromise, that’s an ultimatum.”

Democrats have criticized Republicans for trying to politicize this process to help their party. Every plan offered so far by the Republicans would make the 2nd District more competitive by shifting conservative voters.

The original GOP plan sought to move Knox, Lincoln and Sagadahoc counties into the 1st District and Oxford and Androscoggin counties into the 2nd. According to an analysis by the Bangor Daily News, that shift would add an estimated 8,700 Republicans to the 2nd District.

The new plan submitted by Republicans would add fewer, Goodall said, but he estimated the GOP still would net about 3,000 voters in the 2nd District.

Republicans have countered that the Democrats’ maps simply maintain the status quo and protect the districts of Pingree and 2nd District Rep. Mike Michaud, who are both Democrats.

“Even if they present a one-voter deviation map that focuses on Kennebec County, I don’t know if that’s going to cut the mustard,” Rep. Kenneth Fredette, R-Newport, said Monday.

Congressional redistricting is required every decade to reflect updated U.S. Census data but the process in Maine has moved up two years because of a federal court order. Based on 2010 population data, the difference between the two districts is 8,669 residents, which means roughly 4,300 people must be moved from the 1st to the 2nd District.

Republicans and Democrats each started the process with maps that the other side disliked. They slowly have backed off those initial plans but the commission hasn’t presented a joint map, and it doesn’t appear that will happen before Tuesday.

At a public hearing early last week, about 50 members of the public testified on the process to date. Most favored the simple plans put forth by the Democrats but some who spoke said the Republicans should get their map because they won the 2010 election and elections have consequences.

The commission must vote Tuesday on a plan to send to the Legislative for a special session on Sept. 27. However, the Legislative may end up voting on a different plan, even one that has not yet been presented.