Cannon had refused to refund the contributions as the months-long investigation into Abramoff's lobbying practices unfolded, but the congressman's chief of staff, Joe Hunter, said that with Abramoff's plea agreement Tuesday, it is appropriate to give back the money.

But Cannon won't be refunding $7,000 in contributions from Indian tribes that employed Abramoff. “There's just no reason to do that,” Hunter said.

Abramoff agreed to admit to tricking American Indian tribes out of millions in lobbying fees and sending gifts to members of Congress in exchange for official favors. He pleaded guilty to felony counts of conspiracy, mail fraud and tax evasion, the result of a probe that reportedly could implicate as many as 20 members of Congress.

Utah Democrats have been calling on Cannon for months to return contributions from Abramoff and a wide swath of Abramoff's clients and associates.

"Congressman Cannon should return the money he's taken from any questionable sources," said Wayne Holland, chairman of the Utah Democratic Party. "Cannon's continued refusal to return this dirty money raises serious questions about Cannon's own conduct and the direction of his moral compass."

At least six members of Congress have returned more than $200,000 in campaign contributions in recent weeks that they had received from Abramoff.

“It's always interesting that we give money back to the bad guys,” said Kirk Jowers, director of the Hinckley Institute of Politics at the University of Utah.

Politicians can return tainted money to the source, or they can give it to a charity. “I'm typically more inclined to advise they give it to charity,” said Jowers.

Cannon has already refunded $2,750 in contributions from his former chief of staff, David Safavian, an Abramoff associate and former lobbyist who is also facing federal charges for allegedly lying to investigators.

Hunter said that Safavian suggested to Cannon that he return the funds, but Hunter did not know why.

Safavian's attorney, Barbara Van Gelder, said Tuesday she plans to call Abramoff as a witness in Safavian's April trial, and the plea deal means Abramoff will be able to testify, but it's too soon to tell how that might affect Safavian's case.

Prosecutors say Safavian lied to investigators about a golf trip to Scotland that Safavian took that included Abramoff and Rep. Bob Ney, R-Ohio, while Safavian was chief of staff at the General Services Administration.

Safavian allegedly told investigators Abramoff was not doing business with GSA at the time, although emails in court records show he began consulting with Abramoff about acquiring two pieces of federal property a week after he left Cannon's staff to join GSA.