The trial of Sunni Vice President Tareq al-Hashemi has sparked division over Iraq's judiciary, with his supporters criticising it as politicised while others defend the courts.

Hashemi, a member of the secular Sunni-backed Iraqiya bloc, fled to the autonomous Kurdistan region of northern Iraq after being accused in December of running a death squad, and subsequently left the country.

Hashemi, his staff and his bodyguards face around 150 charges, which he insists are politically motivated. He is being tried in absentia.

"All evidence during the past months indicates that the judiciary was not successful in many things, and the effect on it of politicisation is clear," Hamed al-Mutlak, a leading MP in the Iraqiya bloc and brother to one of Iraq's deputy prime ministers, said.

"We need a separation of powers and to define responsibilities and stop the interference in the work of the judiciary, which is not up to the standard of the Iraqis, though Iraqis were one of the first peoples to adopt laws," Mutlak said.

Earlier this year, a judge sought to have the immunity from prosecution lifted from another leading Iraqiya MP, Haidar al-Mullah, after he accused the judge of being influenced by Prime Minister Nuri al-Maliki.

When asked about the case, Mullah said that "there is an involvement from the executive authority in the work of judiciary."

However, the Iraqi judiciary also has its defenders, especially among allies of the country's premier.

"The judiciary is very neutral and the procedures are correct, legally and constitutionally," said Alia Nsayef, an MP from the Free Iraqiya bloc, which broke away from Iraqiya and is allied with Maliki.

"Many lawmakers were briefed on the investigations and they noticed through the confessions ... and the evidence of the crimes and the assassinations that the crimes are real," she said.

Judicial spokesman Abdelsattar Bayraqdar also defended the courts.

"The accusations that we face during the period of Hashemi's trial are because of the conflict of interest among politicians," Bayraqdar said.

"The trial is public and if we had anything to hide, we would do it in a different way," he said.

"The judiciary in Iraq is like any judiciary in the world -- it is accused of being politicised by the accused people or those who do not like the sentences."

Hashemi's trial opened in May. The next hearing is scheduled for July 8.

The accusations against Hashemi came amid a broader series of intertwined political crises that began with accusations that Maliki was centralising power and moving toward dictatorship, and have escalated into calls for him to be removed from power.

The Hashemi case is not the first time the Iraqi judiciary has been accused of politicisation in recent years.

The Iraqi courts were accused of being under American influence during the trials of officials from President Saddam Hussein's regime, and especially that of Saddam himself, who was sentenced to death and executed in 2006.

"The judiciary was really under American influence during Saddam's trial and today, it moved from American influence to the influence of the political blocs and their struggles," according to independent Kurdish MP Mahmud Othman.