U.S. Sen. Mary Landrieu called Friday on her opponent, U.S. Rep. Bill Cassidy, to produce records that show he performed the work promised LSU for a part-time teaching position.

Landrieu referred to what she called serious allegations “about Congressman Cassidy’s practice of collecting a pay check and benefits package close to $50,000 a year for work that there is no evidence anywhere that the work was ever done.”

Landrieu, a Democrat, is facing Cassidy, a Republican, in a Dec. 6 runoff election for her Senate seat.

The only debate Cassidy would agree to is scheduled for 7 p.m. Monday at WAFB-TV in Baton Rouge. It will be shown on television statewide.

“I am calling on Congressman Cassidy today to bring with him all 63 months of records to our debate on Monday night to explain the situation, to put this to rest,” Landrieu said. She then left the telephone news conference, and her staff continued.

Cassidy and his campaign staff did not respond Friday to four requests for comment.

Landrieu’s campaign alleges Cassidy double-dipped and committed fraud in taking $20,000 a year for a part-time job teaching resident physicians at the LSU medical school operations in Baton Rouge. Sixteen months of time sheets show that Cassidy worked fewer than eight hours a week, which presumably would be 20 percent of a full-time schedule.

The logged hours showed Cassidy working with residents, as doctors in training are called, who were seeing patients as part of their duties at clinics and hospitals. He has said he did not report other hours he worked reviewing case files, visiting with students after hours and other duties.

Ryan Berni, Landrieu’s campaign manager, said Cassidy’s spokeswoman, Jillian Roberts, claimed his LSU paycheck covered expenses, such as medical liability insurance.

“We know now, it’s a fact,” Berni said. “LSU had already covered his medical liability insurance, which is valued at as much as $20,000 to $25,000 a year on top of the $20,000 a year stipend, on top of his $174,000 congressional salary.”

The “close to $50,000” Landrieu referred to includes Cassidy’s $20,000 stipend and the malpractice insurance.

“It’s really important for the voters of this state, who really haven’t heard who Congressman Cassidy is because he’s been hiding behind ‘Obama, Obama, Obama,’ all day long. Now we know. He’s basically a fraud,” Berni said. Cassidy has spent much of the campaign criticizing President Barack Obama, who is unpopular in Louisiana, and trying to link Landrieu to the president.

On page 9 of his financial disclosure to the U.S. House, Cassidy listed the $20,000 income but noted: “Dr. Cassidy is currently teaching students at LSUHSC (LSU Health Sciences Center New Orleans) and salary merely covers his expenses. He does not earn a profit from being employed by LSUHSC.”

When asked for comment, Roberts referred queries to Cassidy’s campaign spokesman, John Cummins, who did not respond.

LSU says it cannot find the documents, including the agreement that outlines the work that was supposed to be done.

Cassidy was supposed to give “20 percent effort,” but that is not defined in available documents.

LSU lawyer Katherine Muslow says the Health Science Center, based in New Orleans, is uncertain whether a letter was ever generated that would outline specifically what work would make up a “20 percent effort” and how Cassidy was to document that labor.

“One was supposed to be created, but it was never done,” Muslow said, adding that the business manager at LSU Earl K. Long Medical Center, the Baton Rouge charity hospital where Cassidy and his residents worked, repeatedly asked medical school executives to detail the congressman’s part-time assignments.

“Everybody’s been looking for the documents,” LSU Health Sciences Center Chancellor Larry Hollier said. “He was being paid out of Baton Rouge Earl K. Long, which is no longer there.”

Cassidy had worked at the LSU charity hospital for two decades before taking his seat in Congress in January 2009. He got permission from the U.S. House to continue teaching part time; congressmen are forbidden from treating patients as part of a private practice.

Cassidy often appeared on television news programs and gave speeches criticizing the Democratic-backed Affordable Care Act. Inevitably, it was mentioned that Cassidy had treated Medicaid and uninsured patients throughout his career and that he continued to work with LSU part time, even while in Congress. Commercials in the Senate campaign often featured Cassidy wearing hospital scrubs, and his speeches almost always mentioned his part-time teaching at LSU.

The hospital was closed in April 2013. Its operations were transferred to Our Lady of the Lake Regional Medical Center, also in Baton Rouge. His time sheets from Lake are neatly typed and cover the entire time from the move through March 2014, when Cassidy stopped working part time because of his campaign to unseat Landrieu. The missing records are primarily from the time when the LSU operated out of the Earl K. Long Center.

LSU Health Sciences Center executives have not publicly complained about Cassidy’s work.

Marsha Shuler, of The Advocate Capitol news bureau, and Gregory Roberts, of The Advocate Washington bureau, contributed to this report. Follow Mark Ballard on Twitter, @MarkBallardCNB. For more coverage of government and politics, follow our Politics Blog at http://blogs.theadvocate.com/politicsblog.