Democratic Missouri Senator Claire McCaskill billed taxpayers approximately $1,220 for an airplane trip to a Democratic political event, her spokesperson confirmed CBS News.
Earlier this week, McCaskill wrote a check for more than $88,000 to the Treasury Department, after reports surfaced that she had, over the course of four years, billed to taxpayers $76,000 for 89 flights on a charter plane she co-owns with her husband and other investors.
A spokesperson for the congresswoman, who has throughout her Senate career made a point of pushing for increased government oversight into congressional expenditures of taxpayer dollars, insisted that the flights did not violate any laws or Senate rules. She added, however, that McCaskill was was happy to reimburse the funds for the sake of "the optics of the bigger picture."
The Associated Press notes that while members of Congress often use chartered flights to for business purposes, it is unusual for members to travel professionally in a plane in which they hold a personal stake.
"Senate rules do not specify whether senators can be reimbursed for use of a personal aircraft for official use, although staffers and senators are reimbursed when they use their cars for personal business," writes Henry Jackson of the Associated Press.
McCaskill press secretary Maria Speiser originally maintained that McCaskill's use of the private plane was in accordance with Senate rules.
"Sen. McCaskill has been very careful flying on taxpayer dollars," Speiser told POLITICO earlier this week. "She has only paid for the use of her plane as required by the Senate rules, and there has been no profit to her or her family. She's glad there's transparency - that's why people can see this information."
"Sen. McCaskill is interested in three things when it comes to using a charter plane to travel in Missouri: doing it as cheaply as possible, following the letter of the law and doing it as rarely as possible," she continued. "However, despite all of this being the case, she understands that the optics of the bigger picture may not seem as cut and dry, so she's more than happy to address that concern as well."
Politico reported on Thursday night, however, that at least one of those flights - a 2007 trip from St. Louis to Hannibal, MO, and back - was for political purposes -- which would apparently put McCaskill in violation of Congressional ethics rules. (McCaskill spoke at an annual event for Hannibal's Democratic party.)
Speiser said the trip was likely billed in error and that McCaskill was "embarrassed by the mistake." She also noted that the expenses for the trip had since been reimbursed.
"Sen. McCaskill is embarrassed by this mistake," she said in a statement to CBS News. "Fortunately, all the expenditures related to the plane have already been repaid to the government. Because of the strict disclosure rules for domestic travel, this mistake was uncovered and can be addressed. This flight was reported to the public at the time it occurred, but the mistake was not caught at that time. She thinks there should be public disclosure like this for all flights, including foreign."
The error may come back to haunt McCaskill in what is expected to be a tough 2012 re-election campaign - particularly since she has made a name for herself as pro-reform, pro-oversight candidate.
In unveiling a set of proposals to cut expenses and provide greater oversight on Capitol Hill in February, McCaskill argued that members of Congress should not allowed to make their own rules.
"There's nothing that irritates Americans more than the fact that some members of Congress think they are entitled to their own set of rules," McCaskill said in a statement last February. "Too many people in Washington live in an alternate reality. It's time for that to stop."
Already, Missouri Republican Ed Martin, a potential 2012 opponent, is attempting to capitalize on McCaskill's woes: He has created the website "Air Claire," which depicts a jet superimposed over the Senator's head, and which asks for donations of $89 - "the price of a one-way plane ticket to send her home!"