WASHINGTON - US Attorney General Alberto Gonzales is getting a two-day reprieve in his high-stakes appearance before the Senate Judiciary Committee because of the shooting rampage at Virginia Tech.

Attorney General Alberto Gonzales appears at a round table discussion with law enforcement officials about his Project Safe Childhood initiative in Boston in this March 30, 2007 file photo. [AP]

Democrats raised new questions about the roles he and President Bush played in the dismissal of eight US attorneys.

Gonzales had been scheduled to make his first appearance Tuesday before Congress in the uproar over the firings. The Senate Judiciary Committee postponed the hearing until Thursday after the shooting spree on the Blacksburg, Va., campus.

"I'm sure that he will want to be dealing with the matters of the shooting," Committee Chairman Patrick Leahy (voting record) of Pennsylvania, agreed that the delay was appropriate.

Sen. Charles Schumer (voting record), D-N.Y., said Monday that Gonzales' former chief of staff, Kyle Sampson, told the Senate panel's investigators during an interview Sunday that the attorney general and Bush had a conversation in October in which the president mentioned concerns about David Iglesias, the US attorney in New Mexico who was later fired.

Gonzales related the conversation to Sampson just last month, Schumer said.

Bush told reporters last month that he recalled having a conversation last fall with Gonzales about complaints from senators about prosecutors, "but I never brought up a specific case or gave him specific instructions."

"As recently as March 26 the attorney general told NBC News that he did not remember a conversation with the president," Schumer said. "But only three weeks earlier, according to Sampson, he did specifically remember such a conversation."

Iglesias has maintained that he was fired after Sen. Pete Domenici (voting record), both R-N.M., complained that he was not moving aggressively enough to bring indictments before November's election in an alleged kickback scheme involving New Mexico Democrats.

Domenici and Wilson have acknowledged talking with Iglesias by phone weeks before the election but have denied trying to put any pressure on him.

The White House has pushed for Gonzales to testify as soon as possible, and the long-scheduled hearing is widely viewed as the attorney general's last chance to quiet a controversy that has prompted calls in both parties for his resignation.

In prepared testimony for the hearing, Gonzales said he has "nothing to hide."