Washington ? A group with Democratic ties is filing complaints against Rep. Billy Tauzin of Louisiana and Sen. Richard Shelby of Alabama, saying they may have solicited campaign donations from a utility in exchange for legislative assistance. Both men deny soliciting the donations or providing any help.

Citing internal documents from Westar Energy of Topeka, Kan., Citizens for Responsibility and Ethics in Washington questioned whether Tauzin and Shelby violated rules of professional conduct for lawyers, filing the complaints with disciplinary panels in the home states of the two, who are attorneys.

At issue are more than $55,000 in campaign donations from Westar and its executives last year to members of Congress. Westar was seeking a legislative exemption from regulatory oversight; the exemption could have helped the company save billions of dollars. Tauzin is chairman of the House Energy and Commerce Committee, and Shelby is chairman of the Senate Banking Committee.

Internal Westar e-mails outline a plan for making campaign donations “to get a seat at the table” of a House-Senate conference committee considering the exemption.

The documents, which surfaced recently in an internal probe of the company, state that Tauzin and Rep. Joe Barton, R-Texas, have requested a donation for another House Republican “in lieu of contributions made to their own campaigns.” Shelby “is our anchor on the Senate side,” and “he’s made a substantial request of us for supporting” the senator’s former chief of staff in a congressional race, the documents add.

Tauzin said he was unaware that Westar was seeking the exemption and that he never solicited the company for donations. Shelby’s office says he made no request of Westar for donations and rejected a request to write a letter to another senator on the company’s behalf. Barton and other congressional Republicans dropped their support for the exemption when a federal grand jury began investigating the company.

“Never in more than 31 years of public service has anyone ever questioned my official conduct,” Tauzin said Wednesday. “I am absolutely confident that this politically motivated complaint will be properly dismissed.”