African National Congress (ANC) president Jacob Zuma's controversial remark that the Constitutional Court is "not God" was merely a plea for judges not to take political sides, ruling party treasurer-general Mathews Phosa said on Wednesday.

Phosa told the Cape Town Press Club he rushed to get clarification from Zuma after he appeared to question the role of the country's highest court in an interview published in Independent Newspapers' titles last week.

"The morning after, I had a discussion with him because I wanted to be clear the context in which it was said."

But Phosa said he was reassured that "there is no ANC policy that we must change the Constitutional Court".

He said Zuma took issue with remarks attributed to Deputy Chief Justice Dikgang Moseneke just after the ANC's watershed conference in Polokwane in 2007 where Zuma was voted in as party leader.

Moseneke reportedly told guests at a birthday party: "I want to use my energy to help create an equal society. It's not what the ANC wants or what the delegates want: it is about what is good for our people."

Phosa said Zuma felt it was not healthy for judges to "reduce themselves" to expressing personal opinions about political parties.

"They should not show their preferences, they should not lower their guard."

In the interview published three days after the National Prosecuting Authority withdrew fraud and corruption charges against Zuma, the Presidential frontrunner said a democracy could not have "people who are almost like God".

He said Constitutional Court judges were fallible and called for the Judicial Service Commission to review the status of the court.

"As the President of the country... I think it's important to engage them, to raise these kinds of issues in their organisation," he said.

On Wednesday, former Chief Justice Arthur Chaskalson appeared to respond to Zuma's remarks in an opinion piece published in the Cape Times and The Star that asserted the independence and impartiality of the highest court in the land.

"On no occasion throughout the nearly 11 years that I presided over that court, did I ever hear or think that one of its judges was allowing personal considerations to interfere with his or her judicial duties."

Chaskalson called on government to respect the courts.

"The binding force of decisions of the Constitutional Court has always been respected by the President and other organs of State, even when decisions have gone against them," he wrote.

"This is important, for if the government does not respect the courts and obey the law, it can't expect or require others to do so."