At the age of 90, Sen. Robert Byrd is increasingly frail. He usually relies on a script. And he's taken to a wheelchair since a recent fall and two stints in the hospital.

But the longest-serving senator in history had a message Wednesday for colleagues and staff aides who whisper that maybe he's not up to chairing the powerful Appropriations Committee: "Shut up!"

Byrd, D-W.Va., made his remarks to reporters after chairing a two-hour hearing on the administration's Iraq war funding request, a session that the media and some of Byrd's colleagues viewed as a key test for the chairman.

Speculation about Byrd, especially as a difficult debate on the war funding bill approaches, was part of a recent meeting of top Senate Democrats, and his future has received almost daily coverage by Capitol Hill newspapers such as Roll Call.

Byrd performed steadily Wednesday, even though he relied on prepared statements when opening the hearing and asking questions of administration witness Jim Nussle, head of the White House budget office. But Sens. Daniel Inouye, D-Hawaii, and Thad Cochran, R-Miss., did so as well

Majority Leader Harry Reid, D-Nev., who has long had a good relationship with Byrd, has stood by him previously and did so again Wednesday.

"Senator Reid spoke to several members of the committee after the hearing, all of whom said that he did a commendable job," said Reid spokesman Jim Manley.

Byrd also received public promises of support from several members of the panel, including those whom he suspects of favoring easing him out.

Sen. Dick Durbin, D-Ill., grew testy with reporters after the hearing.

"Would you stop? You guys are becoming so macabre. Really, you ought to stop," Durbin told reporters. "This is not fair. It really isn't. This poor man is working himself as hard as he can and doing a good job and all you can do is kind of boil the pot a little."

"Senator Byrd is chairing the committee and is doing a good job," said Sen. Byron Dorgan, D-N.D.

Still, it's likely that Byrd will rely on fellow panel members when the Senate debates the Iraq funding bill next month. Last year, Sen. Patty Murray, D-Wash., stood in as floor manager for much of the time.

The anonymous leaks to the media about Byrd have had the probably unintended effect of shoring up support for him as senators felt compelled to make vows of loyalty, both privately and publicly. Even in his weakened condition, Byrd wields considerable power.