Senate Appropriations Chairman Robert Byrd (D-W.Va.) is expected to chair a widely- anticipated hearing on the Iraq supplemental spending bill on Wednesday, amid continued questions over whether the frail 90-year-old lawmaker can still handle the job.

Byrd’s office has yet to formally announce the hearing, but appropriators in both parties said Tuesday they’ve been put on notice to expect a mid-morning vetting of the $100-billion-plus measure. Those Senators said they anticipate Byrd will fulfill his duties as chairman during the session, which is likely to feature testimony from Office of Management and Budget Director Jim Nussle.

“It’s a very important hearing and Senator Byrd announced that it’ll be held on Wednesday, and I’ll be there,” said Senate Majority Whip Dick Durbin (D-Ill.), who sits on the Appropriations Committee.

All eyes will be on Byrd to see how he performs Wednesday following last week, when Democrats began quietly discussing whether Byrd remains capable of chairing Appropriations, especially as the politically sensitive supplemental heads to center stage.