The lengthy, town-by-town recount of nearly 300,000 ballots cast in Maine 2nd Congressional District race will begin Thursday morning, according to the Secretary of State’s office.

Republican U.S. Rep. Bruce Poliquin requested the recount after a tabulation of the ballots using Maine’s ranked-choice voting system showed him trailing Democrat Jared Golden by 3,509 votes. Poliquin is also challenging the constitutionality of ranked-choice voting in court.

The recount is expected to take up to four weeks to complete as teams from the two campaigns hand-count each ballot in every municipality, setting aside any disputed ballots. The process repeats itself for each round of ranked-choice voting as the teams tabulate the second- and third-choice preferences of voters whose candidates were eliminated from contention.

Secretary of State Matt Dunlap’s office announced Monday that the recount will begin at 9 a.m. Thursday in Room 110 of the Elkins Building, which is located at 19 Elkins Lane on the former Augusta Mental Health Institute campus. Members of the public and the press can watch the recount, although the process will be suspended from Dec. 24 to Jan. 3 for the holidays.

Maine State Police will be sent this week to retrieve paper ballots from municipalities that sent digital images of scanned ballots to Augusta for the ranked-choice tabulation on Nov. 15.

“About 1/3 of the CD2 ballots are already in hand: The ballots from all hand-count municipalities in Congressional District 2 have been retained at the secure tabulation site from the initial tabulation effort,” Dunlap’s office said in a press release.

“Additionally, all ballots from Hancock County are on hand due to a county Judge of Probate recount. Maine State Police will collect additional ballots as directed by the recount supervisor.”

Maine’s 2nd District race is the first congressional contest in the nation to be decided by ranked-choice voting. This will also be the first time the Secretary of State’s Office conducts a recount of a ranked-choice election.

The final tally of the ranked-choice runoff had Golden — a Marine Corps veteran and state lawmaker from Lewiston — leading the Republican incumbent 142,440 votes to 138,931. Maine’s lengthy history of recounts suggests that Poliquin is unlikely to overcome a 3,509-vote deficit, which is more than 1 percent of the votes cast in the election.

The recount is scheduled to begin a day after a judge in U.S. District Court in Bangor hears oral arguments on Poliquin’s lawsuit challenging the constitutionality of ranked-choice voting. The incumbent congressman has also asked Judge Lance Walker to order a new election.

Workers from the Maine Secretary of State’s Office, top left, sort ballots Nov. 14 as observers watch from outside the secure area, as the ranked-choice voting tally for Maine’s 2nd Congressional District continued in the Elkins Building in Augusta. (Joe Phelan/Kennebec Journal)