More lawmakers are joining the chorus calling for a member of the commission probing the Sept. 11, 2001, attacks to testify before the panel, saying that as a former high-ranking Justice official in the Clinton administration, she has a conflict of interest.

Thirteen U.S. senators recently asked Thomas Kean and Lee Hamilton, chairman and vice-chairman of the National Commission on Terror Attacks Upon the United States (search), to reconsider their decision on allowing former Deputy Attorney General Jamie Gorelick (search) to publicly testify before the panel.

The senators wrote that they "particularly interested" to learn that the Gorelick has already testified before the commission in private, "and we presume not under oath."

The lawmakers wrote that there are "significant unresolved differences" in the public statements of Gorelick and Attorney General John Ashcroft (search), and others involved in the "wall" issue — separating criminal and terrorism/intelligence gathering investigations.

"Conflicting versions of who created the wall, how the wall was created, when it was created, and what dots were not connected because of it, all require that the commission pursue fully the facts," the senators wrote.

President Bush and Vice President Dick Cheney (search) met Thursday behind closed doors with the panel.

Democrats say the president abdicated his responsibility before the attack, and Republican lawmakers are charging that Gorelick should resign from the panel altogether.

Sen. Kit Bond, R-Mo., pointed out that it was Gorelick and Hamilton who were most vocal in calling for National Security Adviser Condoleezza Rice (search) to publicly testify after she spent about four hours with the commission behind closed doors.

"I think that standard not only applied to Dr. Rice ... I think that same standard applies to Ms. Gorelick even though she is a commissioner," Bond told Fox News on Thursday. "She knows more about what happened than almost any other witness they could call before that commission."

The Justice Department released documents publicly on Wednesday that were given to the commission on Tuesday. The documents show that Gorelick was responsible for signing off on the new policy of separation and rejecting criticism from U.S. prosecutors who feared it could undermine future efforts to stop terror attacks.

The documents show that despite public comments to the contrary, Gorelick was heavily involved in Clinton Justice Department rules that fortified or heightened the wall separating criminal and terrorism/intelligence gathering investigations.

Gorelick came under fire from Ashcroft during his recent testimony before the commission.

He released a previously classified 1995 memo written by Gorelick that had instructions to "more clearly separate" counterintelligence from criminal investigations. Ashcroft said this "wall" was a major barrier to terrorism probes.

The Justice documents released Wednesday also show sharp criticism from Mary Jo White, the former U.S. attorney for the Southern District of New York, whose office prosecuted the terrorists convicted in the 1993 World Trade Center bombing. That office also indicted Usama bin Laden for the 1998 bombings of two U.S. embassies in Africa.

"It is hard to be totally comfortable with instructions to the FBI prohibiting contact with the United States Attorneys' offices when such prohibitions are not legally required," White wrote in a June 13, 1995, memo to then-Attorney General Janet Reno.

White wrote that the new policy would leave prosecutors blind to ongoing terror investigations and could create arbitrary lines of communication.

A top aide to Gorelick, Michael Vatis, wrote that Reno should ask for White's proposal that U.S. attorneys' offices should be notified of ongoing terrorism investigations at the outset. Vatis wrote that the request seemed to seek special treatment for White's office.

Gorelick reviewed the Vatis memo and sent her handwritten approval of it to Reno.

"We now have had public statements and documents by people directly involved in the Department of Justice that it [actions of the Clinton Justice Department] was a significant impediment" to the War on Terror, Bond said. "I think the public needs to know more about the wall as well."

Gorelick has said that she will not resign, and commission chairman Thomas Kean and other panel members — even Republicans — have said she is doing a fine job on the panel and will not ask her to leave.

"I have worked hard to help the American public understand what happened on Sept. 11," Gorelick wrote in an opinion column published April 18 in The Washington Post. "I intend — with my brethren on the commission — to finish the job."

"I think she served with great honor," Sen. Joe Lieberman, D-Conn., told Fox News on Thursday. "She's been defended by Republican members of the commission and she ought to finish the job.

"I think these commissioners have risen to their national responsibility here" to try to arrive at a "unanimous report that's constructive," Lieberman continued. "So I'm very optimistic."

The Justice documents were released per the request of U.S. Sens. John Cornyn, R-Texas, and Lindsey Graham, R-S.C.

"These documents show what I've said all along: Commissioner Gorelick has special knowledge of the facts and circumstances leading up to the erection and buttressing of 'that wall' that, before the enactment of the Patriot Act, was the primary obstacle to the sharing of communications between law enforcement and intelligence agencies," Cornyn said in a statement.

"This is a person with knowledge of relevant facts. Either the commission wants the whole truth, or it does not. If it does, she should appear in public testimony so that the families of the victims, the American people and the Congress can have a full and complete picture of what led to the failures of 9/11."

Fox News' Major Garrett, Liza Porteus and Anna Stolley contributed to this report.