WASHINGTON - Two leading Senate Democrats called yesterday for a vote of no confidence in Attorney General Alberto R. Gonzales, and political pressure for his resignation intensified amid revelations about the plan to dismiss U.S. attorneys and Gonzales' role in a 2004 government crisis.

Sources yesterday identified four additional prosecutors who were considered for termination, bringing to 30 the number who were placed on a Justice Department firing list between February 2005 and December 2006. That is about a third of the 93 U.S. attorney positions. Nine were ultimately fired.

Hoping to pounce on Gonzales' sagging support among Senate Republicans, Sens. Charles E. Schumer (D., N.Y.) and Dianne Feinstein (D., Calif.) said they would offer the no-confidence resolution on the Senate floor as early as next week.

The resolution would have no force of law, but Democrats hope it would raise the political stakes for Gonzales and Republicans who vote to support him.

"Any faith that he can run or manage the department is gone," Schumer said. "It's going to be very surprising if we get fewer than 60 votes."

Gonzales continued to lose backing yesterday among GOP lawmakers as Sen. Norm Coleman of Minnesota became the sixth Senate Republican to call for his resignation.

Sen. Arlen Specter (R., Pa.) predicted that Gonzales would resign once Congress completed an inquiry into the U.S. attorney firings because he would be "unable to perform his duties."

"I have a sense that when we finish our investigation, we may have a conclusion of the tenure of the attorney general," Specter said.

Gonzales has been under siege for four months because of Justice's shifting explanations for the prosecutor dismissals. Documents released by the department showed that the effort was based in part on their loyalty to the Bush administration and its policies.

Gonzales was further damaged by testimony Tuesday from former Deputy Attorney General James Comey, who described how Gonzales, as White House counsel in 2004, tried to persuade then-Attorney General John Ashcroft to reauthorize a terrorism surveillance program while Ashcroft was in intensive care recovering from surgery. The Justice Department had deemed the secret warrantless program illegal, and Comey, as acting attorney general, had refused to renew it. Comey, Ashcroft, FBI Director Robert Mueller and others threatened to resign over the matter before President Bush intervened, Comey testified.

Sen. Olympia J. Snowe (R., Maine) said Bush "should obviously seriously consider" firing Gonzales over the incident.

Bush, who has strongly supported Gonzales, declined to comment yesterday on whether he had ordered Gonzales and Andrew Card, then Bush's chief of staff, to make the hospital visit.

"There's a lot of speculation about what happened and what didn't happen," Bush said. "I'm not going to talk about it."

In another challenge to Gonzales, House Judiciary Committee Chairman John Conyers Jr. (D., Mich.) and subcommittee chairman Jerrold Nadler (D., N.Y.) called on the Justice Department yesterday to widen the circle of lawmakers briefed on the surveillance program.

In a joint letter, they said that if the administration refused to share information on the program with the Judiciary Committee, it would be "impossible" for the committee to consider any changes the administration is seeking in the wiretap law.

The Washington Post yesterday identified 26 U.S. attorneys included on various firing lists compiled between February 2005 and last December by Kyle Sampson, then Gonzales' chief of staff, and his colleagues.

Sources yesterday identified four other current or former U.S. attorneys who were included on a Jan. 1 list that grouped a dozen prosecutors into three tiers. They include current U.S. Attorneys Matthew Mead of Wyoming and Eric Melgren of Kansas, and former prosecutors James Vines of Nashville and Michael Heavican of Nebraska.

None responded to requests for comment yesterday. The four names do not reappear on any of Sampson's other lists, according to the sources, who are familiar with the documents, which have been withheld from the public. The same Jan. 1 list includes U.S. Attorney Christopher Christie of New Jersey, who also appears on a Nov. 1 list, sources said.

Several prosecutors considered for termination said in interviews that they had received no complaints about their performance and did not know why Sampson included them. Sampson's attorney declined to comment.