Those drunk with power in South Africa will get their comeuppance, said Archbishop Desmond Tutu on Sunday.

"Those who become arrogant, who become drunk with power, who seemingly are unassailable: Watch out," said Tutu at a memorial service for veteran anti-apartheid politician Helen Suzman in Johannesburg.

"The Nats [National Party] were returned election after election with increasing majority. Waar is hulle nou? [Where are they now?]

"Those who hold power and are afflicted by arrogance must know they are ultimately going to get their comeuppance, for ultimately power is service."

Tutu said Suzman's legacy was of a true public service.

"Don't let sideline people, because of their ethnicity or political affiliation, [have power].

"Ours [SA] is a scintillating success waiting to happen," he said.

Earlier, photographers swarmed around Thabo and Zanele Mbeki as they arrived and took their seats in the front row of the Great Hall at Wits University for the memorial.

Also in attendance were Graca Machel, former DA leader Tony Leon, Constitutional Court Judge Albie Sachs and head of the Suzman Foundation Raenette Taljaard.

Other speakers at the event with Tutu, included IFP Leader Prince Mangosuthu Buthelezi, DA leader Helen Zille, Suzman's fellow apartheid activist and academic Dr Mamphele Ramphele, former Progressive Party politician Colin Eglin, businessman Nicky Oppenheimer, deputy chief justice Dikgang Moseneke, Centre for Development Enterprise head Ann Bernstein, actor Pieter Dirk-Uys and Suzman's daughter Frances Suzman Jowell and her grandson Daniel Jowell.

SA Institute of Race Relations executive director John Kane-Berman would serve as master of ceremonies.

Suzman died on January 1 aged 91 at her home in Johannesburg. She was generally recognised as the most effective parliamentary fighter against the former National Party's apartheid policies when it was in power.

For 13 years -- from 1961 to 1974 -- she was the sole representative in Parliament of the liberal Progressive Party, forerunner of the Democratic Party.

Suzman retired from a 36-year-long parliamentary career in 1989. During this time she frequently visited prisoners, such as Nelson Mandela and others, demanding better treatment for them and their release.

Suzman received honorary doctorates from a number of leading universities throughout the world and South Africa. Among them were Oxford, Cambridge, Columbia (New York), Harvard, Witwatersrand and Cape Town.

She also received an honorary Fellowship of the London School of
Economics.

Suzman was twice nominated for the Nobel Peace Prize and for the Chancellorship of the University of the Witwatersrand.

After apartheid, she served on the Independent Electoral Commission and the Human Rights Commission.