AUGUSTA – The Republican candidate in a special election that will determine the balance of power in the Maine Senate said Wednesday she will ask for a recount.

“I think that will undoubtedly be the reality,” Sally Vamvakias said after unofficial state totals in the hard-fought Portland-area campaign showed her trailing Democrat Michael Brennan by 20 votes out of nearly 8,000 cast Tuesday.

Vamvakias said she expected to file a formal request with the Secretary of State’s Office as early as Thursday.

Democratic leaders, meanwhile, claimed victory in the race to represent a district comprising parts of Portland, Falmouth and Long Island and thanked more than 200 volunteers they said helped get out the vote.

“It’s great for Democrats to take back a seat that’s been held by Republicans for the last eight years,” said Senate Democratic Leader Beverly Daggett of Augusta.

Messages left through the state Democratic Party office for Brennan, a former four-term state House member, were not immediately returned and there was no answer at his home.

State law requires that state police seize and secure ballots when the margin between first- and second-place finishers is less than 1 percent of the total. While the law presumes a recount, none would be scheduled for Tuesday’s District 27 contest until a candidate requests it, said Deputy Secretary of State Julie Flynn.

State troopers took possession of ballots, which were expected to arrive in Augusta on Wednesday evening and will be kept under lock and key at the State Police Crime Lab, spokesman Stephen McCausland of the state Public Safety Department said.

Brennan of Portland drew 3,284 votes, while Vamvakias, a Maine Medical Center trustee and former University of Maine System trustee, had 3,264.

Independent Philip John Dawson was third with 1,083 votes, followed by Kelly Thompson Fernald of the Green party, with 201 votes, and state Libertarian Party head Mark Cenci, 119.

The special election was held to fill a seat in the 35-member Senate left vacant by the Jan. 14 death of Republican Sen. Joel Abromson of Portland. Pending a final determination in District 27, Democrats hold 17 seats and Republicans hold 16. One member is an independent.

State Democratic Chairwoman Gwethalyn Phillips said a win would provide momentum to help party candidates for governor, the Legislature and Congress in November.

Vamvakias said she had not lost confidence despite Tuesday’s finish.

“I think I ended this race with the absolute feeling I could win the race,” she said.