U.S. Sen. David Vitter can use campaign funds to pay some legal costs from his involvement in an escort service scandal, according to a draft opinion prepared for the Federal Election Commission.

The commission is scheduled to take up the issue Thursday, when it can adopt the report, make changes or ask its staff to redo the recommendation.

The legal expenses stemmed from the Louisiana Republican being tied to a Washington, D.C., escort service operated by Deborah Palfrey, who was convicted of running a prostitution ring that catered to the powerful. She committed suicide about two weeks after her conviction.

Vitter has acknowledged involvement with the service and apologized for what he called a "very serious sin" but has dodged follow-up questions.

He was not charged in the case and attorneys ultimately did not call him to testify at Palfrey's trial, though they said they might.

Vitter's lawyers asked the FEC to rule on whether the senator could use campaign funds to pay about $207,000 in legal costs, and whether his campaign committee could reimburse Vitter $70,000 for fees he already paid.

The funds in question would otherwise go toward the first-term senator's 2010 campaign. He has not said whether he will run again. In its latest statement filed with the FEC, his campaign committee said it had $1.9 million cash on hand as of June 30, and no debts.

The FEC opinion said Vitter could use about $31,000 in campaign funds for responding to inquiries from the Senate Ethics Committee, which eventually decided not to investigate him, and hiring a public relations professional.

But the FEC's staff ruled out using campaign money to pay $85,322 Vitter used to fight subpoenas issued by Palfrey's attorney and $75,212 he was billed by his attorneys for monitoring Palfrey's court case. The opinion said those expenses were not directly tied to his job as a senator.

The draft opinion said a portion of the $70,000 already paid by Vitter and a portion of $15,301 he had been billed for transportation and photocopying could be paid with campaign funds, as long as those expenses were tied to expenditures cleared by the FEC. An exact amount had not been determined.

Vitter's lawyers referred inquiries to the senator's office. A spokesman did not immediately return a call for comment.