The political dogfight over Democratic U.S. Sen. Mary Landrieu’s illegal use of taxpayer funds for campaign charter flights flared up again in earnest Friday, with Republicans that morning claiming the discovery of additional violations and Landrieu that afternoon releasing a review of all her flights that acknowledged more wrongful payments than the Republicans alleged.

Landrieu, a three-term incumbent running for re-election in Louisiana this fall, said her campaign has paid nearly $34,000 to the U.S. Treasury to make good on improper payments since 2002.

“The review I ordered last month found these mistakes stemming from sloppy bookkeeping,” Landrieu said in a prepared statement. “I take full responsibility. They should have never happened, and I apologize for this.”

Landrieu said her office has adopted an accounting system successfully used by other Senate offices to prevent a recurrence of the errors.

As an incumbent Democrat in a Republican-dominated state, Landrieu is a prime target of the Republicans’ nationwide drive to pick up the six seats they need to capture a Senate majority, and polls show a close race in Louisiana. Landrieu’s leading Republican opponents — U.S. Rep. Bill Cassidy, of Baton Rouge, and former Air Force Col. Rob Maness, of Mandeville — have criticized her misuse of her official funds. Republicans and their conservative allies have filed complaints with Senate and federal election regulators, but experts in the field say Landrieu’s undertaking of the review and repayment of the funds could well mean she will not be formally penalized.

The scandal erupted last month when media accounts said Landrieu had tapped her official office expense account for campaign charter flights, in violation of federal law. The first charge involved a flight in November 2013, and Landrieu blamed the wrongful billing on a mistake by the flight operator. A second account questioned another 2013 flight, and Landrieu then announced the in-house review of all her flights since she first was elected to the Senate in 1997. Two other flights, in 2012, were cited in subsequent media accounts, but Landrieu withheld comment pending completion of the review.

Landrieu’s office initially said the review would be released publicly by last Monday, but the results were not disclosed until Friday afternoon.

On Friday morning, at a news conference in Baton Rouge, the Louisiana Republican Party questioned her use of official funds to pay for nine flights from 2000 to 2008 that cost $13,892, according to Jason Doré, the state party’s executive director.

Landrieu’s review of 102 mixed-use flights from 2002 to 2014 flagged 33 that involved some degree of improper payments.

Doré said party officials matched travel expenses claimed by Landrieu with the dates her campaign organization received checks. He said Landrieu’s campaign raised $136,627 on those trips.

“The only conclusion that can be drawn is that she flew into town for a fundraising event,” Doré said. “We don’t have a whole lot of faith that a campaign-funded investigation is going to be independent.”

The information from the Republicans and Landrieu largely coincided, if not exactly. The Republican report included one flight from before 2002. That was the year of a rules change that required officeholders to pro-rate expenses on travel that involved both official business and campaign events, if the campaigning amounted to more than 15 percent of the activities on the trip, Landrieu’s office said. Before then, flights would be characterized entirely as either official or campaign-related, the office said.

Cassidy’s campaign spokesman John Cummins criticized Landrieu for not releasing any flight records from 1997 to 2002.

The source of the illegal payments was Landrieu’s official Senate office account. Each senator is allocated an account by the federal government, with the amount varying depending on the population of the senator’s state and its distance from Washington. Senators are allowed considerable discretion in how they spend the money, but it is limited to official needs, not campaign expenses. Landrieu’s account runs to about $3 million a year, which she primarily uses to cover staff salaries and travel.

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