'Why would Zuma tell the truth this time?'

In a scathing indictment of the effectiveness of parliamentary questions, United Democratic Movement advocate Dali Mpofu contended in the Constitutional Court in Johannesburg on Tuesday that a parliamentary inquiry was needed into the Nkandla scandal.

Mpofu said the 27 question-and-answer sessions with President Jacob Zuma on Nkandla had not yielded any genuine answers.

The EFF, UDM, COPE and the DA are asking the court to force parliament to start impeachment proceedings and set up a committee to grill Zuma on whether he misled parliament on Nkandla.

Chief Justice Mogoeng Mogoeng asked if an official parliamentary inquiry was still needed into Zuma's use of state money to renovate his private Nkandla home.

"You believe the truth will be told this time around?" asked Mogoeng.

Mpofu said: "What happens in a Q&A is the direct opposite of what the constitution describes as 'scrutinise'. There is no opportunity to scrutinise. Those [Q&A] sessions are in [that] respect deficient."

If the parties are successful in their application, a subcommittee of their MPs would be set up to question Zuma on Nkandla. He would be under oath.

EFF advocate Tembeka Ngcukaitobi and Mpofu presented their cases to the court for two hours each.

Mogoeng, Deputy Chief Justice Raymond Zondo and Justice Jody Kollapen were unrelenting in their questioning. They grilled the two lawyers about why it was necessary for the court to get involved in parliamentary processes despite the separation of powers doctrine in law.

They asked Mpofu why a "fact-finding inquiry" was needed to investigate Zuma's offences after the Constitutional Court's earlier judgment and the public protector's extensive report.

Mpofu said it would be a way of getting Zuma to answer questions under oath.