Aides of Harry Reid would neither confirm nor deny a report Tuesday that the Senate majority leader is going to strip Sen. Robert Byrd of his position as chairman of the Appropriations Committee.

Democratic sources have said that Reid is quietly plotting to oust 90-year-old Byrd from the chairmanship and dismiss him from the position of president pro tempore — the seat that is third in line to the presidency, according to a report published Tuesday on Politico.com.

"This is not an authorized hit," a Reid aide told FOX News when asked if the report was the Senate majority leader's way of informing Byrd of the change.

The aide did not deny the substance of the charge, but noted the information came from a source on the "periphery."

The Politico.com report, however, provoked an unusually direct retort from Byrd, D-W.Va., who mentored Reid when the Nevada Democrat came to the Senate more than two decades ago.

"I am disappointed that, according to press accounts, the Majority Leader is talking to others about the chairmanship of the Senate Appropriations Committee," Byrd said in a statement released by his office. "This is the sort of Washington back-room gossip which ill serves the Democratic Party in a year when Democratic unity should be paramount."

In a statement later issued to FOX News, Reid spokesman Jim Manley said Byrd is expected to continue to serve as chairman "unless something changes."

"Senator Byrd has ably served the people of West Virginia as a member of the Democratic caucus and as a member of the Senate Appropriations Committee for more than 50 years."

"At the beginning of each Congress, the Democratic Caucus determines committee membership. Unless something changes, Senator Byrd will continue to be chairman of the Appropriations Committee," Manley said.

According to the Politico report, Reid has not informed Byrd of his plans, but during a recent private meeting with with Sen. Daniel Inouye, D-Hawaii, Reid proposed that Inouye — the committee’s second-ranking Democrat — taking over Byrd’s position by January.

Byrd, who is the longest serving senator in U.S. history, has become increasingly frail in recent months and usually relies on a script.

In April, Byrd responded to rumors that suggested he is no longer able to chair the spending committee by saying "Shut up!"

FOX News' Trish Turner and The Associated Press contributed to this report.