The chief prosecutor in the genocide trial of Saddam Hussein has called for the judge to stand down, saying he is biased towards the former Iraqi leader.
Mr Amiri has tried to avoid confrontation with the defendants
Munqith al-Faroon said defendants had been given too much room to threaten witnesses and make political speeches.
Judge Abdullah al-Amiri rejected the request, saying his approach was based on fairness and 25 years' experience.
Saddam Hussein and six others are on trial for war crimes against the Kurds during the so-called Anfal campaign.
"Defendants have gone too far, with unacceptable expressions and words. Defendants have uttered clear threats," Mr Faroon said at the opening of the latest hearing.
Mr Amiri defended his conduct, saying: "A judge should co-ordinate and make peace so nobody takes advantage of his fairness... I have been working in the judicial system for the past 25 years."
In heated exchanges on Tuesday the former Iraqi leader threatened to "crush the head" of a lawyer of one witness for the prosecution.
In three consecutive days of testimony, witnesses have been giving graphic descriptions of the bombing and imprisoning of Kurds by Iraqi forces.
Testimony continued on Wednesday, with one Kurdish witness, Majeed Amad, saying his village of Sargalow had been bombed for 20 days, forcing residents to flee to Iran.
Observers say the testimony has rankled Saddam Hussein
"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."
Another witness, Omar Othman Muhammad, testified that military aircraft dropped balloons, apparently containing chemical weapons, followed by missiles.
"A couple of them fell near my place. I saw headless bodies and parts of bodies, like arms and legs," he told the court.
At the end of Tuesday's session, correspondents say Saddam Hussein was showing obvious annoyance at damning testimony from a succession of Kurdish witnesses.
He threatened one of the witnesses' lawyers, accusing him of being an agent of "Iranians and Zionists", adding "we will crush his head".
On the opening day of the trial last month, the former Iraqi leader vowed to "hunt down [Mr Faroon] for the rest of my life" if the chief prosecutor's allegation that two Iraqi women were raped during his rule were proved untrue.
The judge, apparently keen to make quick progress, has generally avoided confrontation with the defence, correspondents say.
Saddam Hussein and seven co-defendants have already been tried for the killing of 148 Shias in Dujail in 1982, in a process marked by frequent interruptions by defendants and their lawyers. A verdict in that case is due on 16 October.
The former leader and others, including his cousin Ali Hassan al-Majid, are accused of killing up to 180,000 Kurdish civilians in the late 1980s.
Saddam Hussein and Mr Majid, popularly known in Iraq as Chemical Ali, face additional charges of genocide.