Attorneys for Michael Scanlon, a key figure in the influence-peddling investigation centered on disgraced ex-lobbyist Jack Abramoff, asked a federal judge Friday to amend their client’s plea agreement, pointing to a Supreme Court decision that restricted a public corruption statute to which Scanlon had pleaded guilty.

The amended plea — which would remove references to the “honest services” law that the Supreme Court in June ruled may only apply in cases of bribery or kickback schemes — could reduce Scanlon’s potential prison term or monetary fines.

Scanlon is scheduled to be sentenced in the U.S. District Court for the District of Columbia in October.

Scanlon pleaded guilty in November 2005 to one count of conspiracy to violate federal laws including bribery, mail or wire fraud, and honest services fraud.

A former spokesman for ex-Rep. Tom DeLay (R-Texas), Scanlon once ran his own public relations firm and acknowledged he colluded with Abramoff to overbill American Indian tribes for services.

In a motion filed Friday, Scanlon’s attorney requested that the amended plea agreement would drop any references to honest services fraud, while retaining the remaining charges.

Attorney Stephen Braga, who represents Scanlon along with Plato Cacheris and John Hundley, argued that the Supreme Court decision restricts the “honest services” law only to those cases that involve a fiduciary relationship — such as a public official and constituent — and excludes the charges to which Scanlon earlier pleaded guilty.

“Michael Scanlon’s guilty plea was founded, in substantial part, on the ‘honest services’ fraud statute,” he wrote. “In this regard, Scanlon pled guilty to conspiring with Jack Abramoff to defraud certain of Abramoff’s Native American Indian Tribe clients of their purported right to Abramoff’s ‘honest services’ by paying Abramoff a fee for recommending that those tribal clients hire Scanlon’s company.”

Scanlon attorneys noted in the motion that negotiations with Justice Department prosecutors to amend the plea agreement failed to reach a resolution.

In the meantime, Assistant Attorney General Lanny Breuer testified Tuesday before the Senate Judiciary Committee, arguing for new legislation to supplement the honest services law.

“The Department believes that the Court’s decision has created a gap in our ability to address the full range of fraudulent and corrupt conduct by public officials and corporate executives, and we urge Congress to pass legislation to fill the void,” he said.