In this May 19, 2018 file photo, Betsy Sweet speaks at the Democratic convention in Lewiston. The U.S. Senate candidate agreed on Wednesday to pay back more than $8,000 in taxpayer money used to fund her 2018 gubernatorial campaign. Credit: Robert F. Bukaty | AP

AUGUSTA, Maine — Democratic U.S. Senate candidate Betsy Sweet agreed on Wednesday to repay more than $8,000 in taxpayer money used to fund her 2018 gubernatorial campaign.

An audit of Sweet’s 2018 campaign for the Maine Ethics Commission found Sweet, a Hallowell lobbyist, was reimbursed with money from the state’s Clean Election program for purchases made before she qualified for the program in April 2018. State law says candidates cannot use that taxpayer money for expenses they incur before certification.

Those expenses included costs of renting campaign office space in her home, vehicle travel, utilities and other expenses. They should have been paid for with so-called “seed money,” which is limited fundraising from private individuals allowed so candidates can bridge the gap between getting into a race and qualifying for the Clean Election program.

Commission auditors also found Sweet was reimbursed for $1,950 in phone bills for five different lines, but only one of them was used solely for campaign purposes, while another was only partially used for the campaign. She finished third in the June 2018 primary.

In a memo, Jonathan Wayne, the executive director of the Maine Ethics Commission, said staff discussed some of the travel expenses with Sweet’s campaign in 2018 and the campaign had not kept sufficient records on them, but that the commission deferred judgment on them until the audit. He recommended Sweet be required to pay the funds back.

Sweet initially requested a waiver to not repay the money, but she told the Bangor Daily News last week that she would repay it. Frank O’Hara, Sweet’s gubernatorial campaign treasurer, withdrew her request at a commission meeting on Wednesday.

In her response to the findings, Sweet said she did not submit her mileage and expenses when she should have because it would have added “extreme pressure” to her “overworked and underpaid” staff and volunteers. O’Hara called it “an honest mistake” on Wednesday.

Sweet is one of four Democrats running in 2020 for the party’s nomination to face U.S. Sen. Susan Collins, a Republican, alongside House Speaker Sara Gideon of Freeport, Saco lawyer Bre Kidman and former Google executive Ross LaJeunesse of Biddeford.