BAGHDAD - Prime Minister Nouri al-Maliki moved yesterday to undermine the popularity of the Iraqi journalist who threw his shoes at President Bush, saying the journalist confessed that the mastermind of the attack was a militant known for slitting his victims' throats.

Tensions over the case also spilled into parliament, as a move to oust the abrasive Sunni speaker delayed a key decision on whether non-U.S. foreign troops will be allowed to stay in Iraq beyond New Year's Eve.

Maliki said that in a letter of apology to him, Muntadhar al-Zeidi wrote that a known militant had induced him to throw the shoes.

"He revealed . . . that a person provoked him to commit this act, and that person is known to us for slitting throats," Maliki said, according to the prime minister's Web site. The alleged instigator was not named, and neither Maliki nor any of his officials would elaborate.

Zeidi's family denied the claim and alleged that he had been coerced into writing the letter, in which he was said to have requested a pardon for "the big and ugly act that I perpetrated."

Zeidi's brother Dhargham said it was "unfair" of Maliki to make the allegation about the throat-slitter and described the prime minister as "a sectarian man who is destroying the Iraqi people."

Earlier, another brother, Uday, said that he had met with Zeidi in prison Sunday and that he had expressed no regret for throwing the shoes and "would do it again."

Uday al-Zeidi said he found his brother with a tooth missing and cigarette burns on his ears. He also said his brother told him that jailers had doused him with cold water while he was naked.

"There were bruises on his face and body," Uday al-Zeidi told AP Television News. "He told me that they used an iron bar to hit him when they took him out of the press conference room."

The investigating judge, Dhia al-Kinani, has said the journalist was beaten around the face and eyes when he was wrestled to the ground after throwing the shoes at Bush during a Dec. 14 news conference. The judge said Zeidi's face was bruised but provided no further description.

There has been no independent corroboration that Zeidi was abused once in custody.

Abdul-Sattar Bayrkdar, a spokesman for the Iraqi Higher Judicial Court, said that when the investigating judge took Zeidi's statement last week, the journalist "did not ask to be checked by a medical committee and did not say that he was tortured during the investigation."

Zeidi's trial on charges of assaulting a foreign leader is scheduled to begin Dec. 31. A conviction would carry a sentence of up to two years in prison.

The hurling of the shoes turned Zeidi into an international celebrity and led to huge street demonstrations in support of him.

It also brought to a head a simmering dispute between the parliament's Sunni speaker and Kurdish and Shiite lawmakers seeking to oust him. The speaker, Mahmoud al-Mashhadani, irked lawmakers during a boisterous debate over the case last week by insulting some of them and threatening to resign.

Yesterday, lawmakers unsuccessfully tried to vote Mashhadani out of office. Instead they gave him until today to resign or face an ouster vote later that day.

After the heated closed-door session, Mashhadani tried to force the body to withdraw its opposition to him by threatening to call a recess until Jan. 7 - a week after the U.N. mandate expires for non-U.S. foreign troops to stay in Iraq. He backed down after opposition lawmakers gathered enough signatures to force a vote against him.