BAGHDAD (Reuters) - A new judge expelled a defiant Saddam Hussein from his genocide trial on Wednesday and defense lawyers stormed off in protest after the government sacked the chief judge, throwing the month-old case into turmoil.

The Iraqi government removed judge Abdullah al-Amiri overnight saying he had abandoned his neutrality for stating last week that Saddam was "not a dictator." International legal groups and the U.N. said it eroded the court's legitimacy.

"Take him out of the courtroom," the new judge, Mohammed al-Ureybi, told guards after Saddam launched a tirade and refused to sit down. Saddam accused the new judge of being the son of a government spy before the U.S.-led invasion in 2003.

"Your father was a security agent!" Saddam said. "I knew him. He had an operation here," he added, gesturing at his own abdomen.

"I challenge you to prove that to the public," the judge said dismissively as Saddam was being escorted out.

The U.S.-backed tribunal is trying Saddam, his cousin Ali Hassan al-Majeed, known as "Chemical Ali," and five others for war crimes and crimes against humanity for their role in the 1988 Anfal campaign against Kurds. Saddam and Majeed also face the graver charge of genocide. All could be hanged if convicted.

Wadood Fawzi, a lawyer for Saddam and Majeed, said government pressure was keeping counsel from performing its job.

"The sacking of the judge confirmed our fears that this court lacks the conditions to hold a fair trial," Fawzi said.

"If you wish to leave, that's fine. Then go," the judge said. The defense lawyers filed out of the courtroom.

Ureybi ordered the defendants to be represented by court-appointed lawyers and continued proceedings. After listening to five witnesses recount how their villages were attacked with chemical weapons, he adjourned the court until September 25.

Saddam's six co-defendants remained in the marble courtroom.

"LACK OF INDEPENDENCE"

Government spokesman Ali al-Dabbagh told Reuters the decision to sack Amiri was made by the cabinet in accordance with the Iraqi High Criminal Court Law, which allows the government to transfer judges from the court for "any reason."

But legal rights groups said Shi'ite Prime Minister Nuri al-Maliki's decision to replace the judge a month after the case opened hurt its legitimacy. Some legal analysts say sectarian passions makes it impossible to give Saddam a fair trial.

"(It) confirms the lack of (legal) guarantees and the lack of independence of that court," Leandro Despouy, the U.N. Special Rapporteur on the independence of judges and lawyers told the U.N. Human Rights Council meeting in Geneva.

Richard Dicker, who has been observing the court for Human Rights Watch, said: "The transfer effectively sends a chilling message to all judges: toe the line or risk removal."

In an earlier trial this year, the chief judge quit in protest at government interference. That first case, for killings in a Shi'ite village in the 1980s, was marred by repeated interruptions including hunger strikes by Saddam and defense boycotts. A verdict is expected next month.

The Iraqi High Criminal Court was set up by U.S. forces but is now run by Iraqis with American advisers. Its first two cases have centred on crimes against Shi'ites and Kurds, oppressed under Saddam's Sunni-led rule but empowered after his fall.

The Anfal trial is intended to turn the page on one of the darkest chapters of Saddam's rule. Prosecutors say 180,000 villagers were killed in the 1988 campaign against Kurdish militants, including thousands poisoned by chemical gas.

A team of U.S.-led forensic experts has worked for years unearthing mass graves to assist prosecutors with evidence.

Last week, prosecutor Munqith al-Faroon demanded the judge resign for being too soft, saying he had let Saddam make political speeches and threaten witnesses. Saddam had threatened in court to "crush the heads" of his accusers.

(Additional reporting by Ibon Villelabeitia, Peter Graff and Mussab Al-Khairalla)

© 2006 Reuters