AUGUSTA — Republicans in the Maine Senate will take action Wednesday to provisionally seat Cathy Manchester of Gray, the GOP candidate in a Falmouth-area Senate district election for which the results have been contested since Election Day.

That move — which would likely be successful because it simply requires a majority vote of the Maine Senate, and Republicans have at least 20 seats in the 35-person chamber — would overturn a previous decision by Democratic Secretary of State Matthew Dunlap.

Democrat Catherine Breen appeared victorious by 32 votes, according to unofficial election night results, but a recount in the race showed Manchester won by 11 votes. Democrats did not agree to the results of the recount, and — citing past precedent — Dunlap recommended that Breen be sworn in to represent Senate District 25 until a seven-member Senate study panel makes its recommendation to the full Senate on whether Breen or Manchester should be declared the winner.

Maine law requires that the full Senate vote to determine the winner if both parties can’t agree on a Senate district’s election results after a recount.

Since the contested recount on Nov. 18, Democrats have called for an investigation into a number of ballots that were missing or unclear, as well as 21 ballots for Manchester from the island community of Long Island that Democrats and Dunlap said were not accounted for in voter manifests.

The Democrats’ unwillingness to accept the recount results means that the issue will go to a Senate Elections Committee made up of four Republicans and three Democrats, which will investigate the issue.

Incoming Senate President Mike Thibodeau of Winterport said last week he hoped the matter could be resolved Wednesday when the Legislature convenes for its swearing-in ceremony and the election of constitutional officers.

However, Sen. Roger Katz, R-Augusta, who was chosen by Thibodeau to chair the committee, said Monday he expects the investigation will take longer but that uncertainty about the 21 ballots in question probably results from a “clerical error.”

“The most important thing to Senate Republicans is to make sure that the right person who was duly elected gets seated and that we maintain the integrity of this institution,” Katz told reporters Monday. “We intend to do that.”

Katz said “there’s unlikely to be enough time” for the committee to make a recommendation Wednesday.

Democratic Party Chairman Phil Bartlett and incoming Senate Minority Leader Justin Alfond, D-Portland, held a news conference Monday to reiterate their calls for a thorough investigation of the circumstances that led to the contested recount — including the discrepancy in the total number of Long Island ballots between election night, Nov. 4, and the Nov. 18 recount. They said their primary goal is maintaining Mainers’ trust in the election process.

“We all have a stake in getting this right,” said Bartlett.

Alfond said he has chosen Sen. Stan Gerzofsky of Brunswick, returning Sen. William Diamond of Windham and Sen. Dawn Hill of Cape Neddick to sit on the Senate Election Committee. Other than Katz, no Republican appointees to the committee have been announced.