Tariq Aziz was the first witness to give evidence in defence of Saddam Hussein who, along with seven co-defendants, is charged in connection with the deaths of 148 Shias from the town of Dujail.
An assassination attempt against Saddam was made in 1982 and was followed by the sentencing to death of the 148 people.
Aziz told the court that, while he had nothing to do with the events in Dujail, he was familiar with the period in which there were numerous assassination attempts against government officials, including himself.
Aziz accused one of the parties now in power, the Islamist Shia Dawa of Nuri al-Maliki, the new prime minister, of trying to kill him and Saddam in the 1980s.
"I'm a victim of criminal acts committed by a party presently in
power now. Try them," said Aziz, referring to a hand grenade attack at a Baghdad university in 1980, which he escaped with a broken arm and a few cuts. "They killed dozens of students."
Saddam: Barzan, Ramadan had
nothing to do with the crackdown
In his earlier testimony, Aziz defended the decision of the president to convict those he believed to be guilty of an assassination attempt.
"The president of the state in any country, if faced with an assassination attempt, should take procedures to punish those who conduct and help this operation," he said.
"According to the law, people who support this assassination can also be convicted."
"The president is not guilty, nor are any of the officials in the government, just because they punished those who tried to assassinate the head of state," he told the court in his first public appearance in three years. Aziz is said to be ill with cancer.
Aziz said he was testifying on the behalf of not just Saddam, but also Barzan al-Tikriti, the former head of intelligence and Taha Yassin Ramadan, the former vice president.
"Barzan was my friend. If he had tortured anybody he would have told me," Aziz said.
Saddam spoke out in defence of Barzan and Ramadan, saying they had nothing to do with the Dujail.
Saddam said: "I just let this issue work in the usual way and assigned the security department, not the intelligence who had other work to do. I didn't assign Ramadan to anything in this case."
Aziz's testimony was followed by that of Abdel Hamid Mahmud, Saddam's fomrer director of personal security. Mahmud, a constant companion of Saddam's, described the attack.
"I'm a victim of criminal acts committed by a party presently in power now. Try them"
former deputy prime minister
He said how the conspirators used the traditional custom of sacrificing a sheep in Saddam's honour to mark his car for the assassins with bloody hand prints.
"The day afterwards, the protection force office called. He had found a warehouse full of heavy weapons and a radio set capable of contacting people outside Iraq, obviously Iran, who was involved in the attack," Mahmud said.
He also attempted to absolve Barzan from guilt by explaining that the intelligence service would not have been involved in a domestic affair.
The court was later adjourned to May 29.