Presidential contender Jacob Zuma has again warned that people should not be tried in the court of public opinion, but in courts of law, and said that while transformation of the judicial system is essential, the judiciary must guard against political influences.

Addressing the Gauteng Law Council in Johannesburg yesterday, the ANC deputy president said the judiciary must remain independent of the executive and Parliament and resistant to outside influences. No laws should undermine the basic democratic principle of the separation of the powers of different arms of government.

Zuma, who has been engaged in a marathon series of legal skirmishes with the National Prosecuting Authority, did not refer directly to either the NPA or its Scorpions investigative unit. He did, however, warn that it was worrying if state agencies and institutions of justice were "accused by the public of having political agendas and the integrity of their investigations questioned" - an oblique reference to the Zuma camp's claims that the Scorpions' long-standing arms deal corruption probe into the ANC deputy president was politically motivated.

Zuma warned against passing laws that gave the investigating powers of the police to the judicial system, saying this would open the judicial system to political influence.

Zuma warned that although the separation of powers was entrenched in democracies, history showed the dangers of the judiciary "succumbing to undue influence and manipulation from those in power".

He said South Africa had achieved a human rights culture that needed to be protected and the courts had a critical role to play as "vanguards of human rights". Their conduct and work should be above reproach and be seen to be lawful and independent with people treated equally and the law applied impartially.

It was important to ensure public confidence in the judiciary and respect for its decisions.

"We should also avoid situations where the public has been hysterically provoked around certain cases…

"The current practice where people are found guilty in the court of public opinion can hardly be described as justice. It is perverse and inconsistent with the Rule of Law," he said.

With acknowledgement to Chiara Carter and Cape Argus.