WASHINGTON (CNN) -- Republican Sen. Chuck Hagel of Nebraska joined calls for Attorney General Alberto Gonzales to resign Wednesday, while Democrats questioned whether Gonzales had misled a Senate committee about the administration's no-warrant eavesdropping.

The latest complaints about Gonzales follow testimony by former Deputy Attorney General James Comey on Tuesday. Comey, the No. 2 official at Justice until 2005, said Gonzales tried to get his ailing predecessor, John Ashcroft, to sign off on the surveillance program from his hospital bed after Comey raised questions about the program.

Comey expressed concern to the Senate Judiciary Committee that Gonzales, then White House counsel, and former White House Chief of Staff Andrew Card were trying "to take advantage of a very sick man" by going to Ashcroft. (Watch Comey recall the worst night of his life Video)

In a written statement Wednesday, Hagel -- who is considering a run for president -- said the "honesty and capability" of the attorney general must be unquestioned, and that Gonzales "can no longer meet this standard."

"He has failed this country. He has lost the moral authority to lead," Hagel said.

The White House has stood behind Gonzales, who began working for Bush while the president was governor of Texas in the 1990s. White House spokesman Tony Snow disagreed with Hagel's assessment of the attorney general and said Gonzales retains Bush's support.

"Jim Comey gave his side of what transpired that day," Snow said. "The president still has full confidence in Alberto Gonzales."

Hagel has been increasingly estranged from the Bush administration, even raising the prospect of Bush's impeachment over the war in Iraq during an interview in April's Esquire magazine.

But several other Republican lawmakers -- including Sens. John McCain of Arizona, John Sununu of New Hampshire and Tom Coburn of Oklahoma -- have called for Gonzales to resign over the firings of at least eight U.S. attorneys last year.

Another Republican, Kansas Sen. Pat Roberts, suggested to The Associated Press on Wednesday that Gonzales should consider stepping down: "When you have to spend more time up here on Capitol Hill instead of running the Justice Department, maybe you ought to think about it."

Gonzales has said he wants to put the controversy behind him, but congressional investigators say the basic question behind the firings -- who decided which prosecutors to fire and why -- have yet to be answered.

The Justice Department on Wednesday told an angry Senate Judiciary Committee chairman it does not have documents described in a subpoena that demands all materials relating to White House political adviser Karl Rove's possible involvement in the U.S. attorney firings.

Instead, it said, Rove's lawyer must have them.

The response from a top Justice Department official came just hours after the chairman, Vermont Sen. Patrick Leahy and the panel's top Republican, Sen. Arlen Specter of Pennsylvania, chastised Gonzales in a letter for ignoring the subpoena's Tuesday deadline. (