At the opening of the latest hearing, prosecutor Munqith al-Faroon said defendants had gone too far, with “unacceptable expressions and words”.
“Defendants have uttered clear threats. The chief prosecutor's office requests the judge step down from this case," Mr Faroon said.
Presiding judge Abdullah al-Ameri dismissed the demand.
"The judge should coordinate and make peace so nobody takes advantage of his fairness... I have been working in the judicial system for the past 25 years," Mr Ameri said.
Saddam is standing trial for genocide and other charges over the brutal Anfal campaign of 1987-1988 in which prosecutors say 182,000 Kurds were slaughtered.
He faces court with six other former aides, including his cousin Ali Hassan al-Majid, dubbed "Chemical Ali" and if found guilty they face execution by hanging.
Defence lawyers argue that Saddam and his former regime were engaged in a necessary counter-insurgency operation.
Since the trial opened last month, Saddam has often threatened the prosecutor and questioned witnesses who have given graphic testimony against his forces over the Anfal campaign.
Kurdish witnesses take stand
On Wednesday, four new Kurdish witnesses continued their tirade against Saddam and the other accused, before the trial was adjourned to Thursday.
The first witness of the day, Majeed Ahmad, described how his village was bombed with chemical weapons "just before Anfal".
He said the bombing went on for 20 days in Sargalow, a village north of Sulaimaniyah, and that all residents fled to Iran.
"When the villagers returned to Iraq they surrendered to the Iraqi army and were sent to prison. We have not heard from them since then."
Omar Othman Mohammed, a peshmerga fighter from Sulaimaniyah, accused Majid for leading the attacks and using chemical bombs.
"He (Majid) killed a large number of our peshmergas, civilians and members of the opposition Dawa and communist parties," he said, referring to a bomb attack on March 22, 1988.
"The warplanes hovered over the region and dropped balloons, apparently full of chemical weapons. Then missiles followed. A couple of them fell near my place. I saw headless bodies and parts of bodies, like arms and legs."
Another witness, Sadoon Khider Gader, also gave a gruesome account of how dogs were set free on prisoners killed in detention centres.
"They (the prisoners) were badly treated and those who died were carried by their mates outside" of the detention centre and buried, said Gader, who lost his two sons.
"We saw dogs eating them (the corpses) through the windows."
Salah Gader Mohammed Ameen broke down in the witness box as he testified, saying his father, mother and two brothers disappered in the Anfal attacks, only to be told that in 2004 that their bodies were found in mass graves.
"Nothing will compensate the loss of my father and mother when I was 10 years old," he said wiping his tears.