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Former House Speaker Newt Gingrich has joined the chorus of Democrats and some Republicans suggesting that it's time for Attorney General Alberto Gonzales to leave his post over the botched explanation of the firings of eight U.S. attorneys.

Gingrich argued that the Justice Department doesn't need to give any justification for the decision to dismiss the federal prosecutors, who serve at the pleasure of the president. But as a result of misstatements and backtracking, Gonzales has made it impossible for the department to conduct its business since continuous questioning from congressional Democrats distracts officials, he said.

"The public would be much better served to have another attorney general," said Gingrich, who is considering a possible 2008 presidential run. "I cannot imagine how he's going to be effective for the rest of his administration. They're going to be involved in endless hearings."

Transcript: Newt Gingrich, Senator Charles Schumer on 'FNS'

Gonzales, a former White House counsel who became attorney general in 2005, is scheduled to testify April 17 before the Senate Judiciary Committee, which is investigating the firing of eight federal prosecutors.

It is a congressional showdown believed to be a make-or-break appearance for Gonzales. The committee also has demanded testimony from former White House officials such as Karl Rove and former counsel Harriet Miers about the extent of White House involvement in the decision-making.

An earlier appearance by Gonzales in front of a Senate appropriations subcommittee was cancelled by the Democratic chairwoman who said the Justice Department's business could not be discussed until the attorney general testified on the firings.

On Friday, Monica Goodling, the Justice Department's liaison to the White House, abruptly quit after telling Congress she would not testify. Former Gonzales chief of staff, Kyle Sampson, also resigned after lawmakers questioned the attorney general's assertion that he was not directly involved in the decisions to relieve the attorneys from their posts.

Sampson voluntarily appeared before the Judiciary Committee and said he did not think Gonzales was being honest when he denied his role in the firings. But Sampson denied any of the firings were the result of retaliation against the attorneys over their decisions whether or not to prosecute individuals in cases that could be politically damaging to Republicans.

Gonzales has since apologized for saying he did not have a role, but Democratic Sen. Charles Schumer, who is head of the subcommittee leading the probe, said the controversy demonstrates a leadership failure at the department.

"The gravity of this situation is shown by the fact that several Republicans have called for the attorney general to resign," he said. "The fact that the attorney general is the president's friend and president's counsel for years does not alone make him qualified for attorney general."

Several Republicans have joined the calls for Gonzales' resignation, including Sens. John Sununu of New Hampshire and Gordon Smith of Oregon and Reps. Dana Rohrabacher of California, Tom Tancredo of Colorado and Lee Terry of Nebraska.

But administration allies like Sens. Jon Kyl of Arizona and John Cornyn of Texas have suggested that Gonzales could still recover if he explains himself quickly.

"I think the confusion and the ham-handed way that these firings was done certainly undermines the confidence of the Justice Department," Kyl said Sunday. "And part of his effort to come up and testify before the Hill will be to restore some of that confidence."

Gingrich, who appeared with Schumer on "FOX News Sunday," said the political scandal surrounding the firings is Gonzales' own doing and could have been avoided. It may not be politically survivable, he said.

"This is the most mishandled, artificial, self-created mess I've seen in all the years in my public life," Gingrich said. "The buck has to stop somewhere, probably with the attorney general."

Elsewhere, Sen. Carl Levin, D-Mich., said he was surprised that Gonzales hasn't yet quit.

"He told the American public and he told the Congress that the reason that those U.S. attorneys were asked to depart was because of performance shortfalls. That was not true. That was not true and it hurt the morale of the U.S. attorneys across this country when he misstated, misinformed the American people ... I don't believe you can have an attorney general that people do not trust."

The Associated Press contributed to this report.