Former deputy state president and Speaker of the House of Assembly Alwyn Schlebusch died in Pretoria on Monday at the age of 90, his son said.
Schlebusch, who served as a National Party MP for two decades and held several cabinet portfolios, was admitted to the Pretoria East Hospital two weeks ago with pneumonia, and was in the intensive care unit when he died.
His son Sarel said he and his sisters, Isabel Scholtemeijer and Betsie Pretorius, were with their father through Sunday night, and until his death.
"He was in a great deal of pain: they sedated him, and he died very peacefully," his son said.
He said the family was discussing with the presidency plans for a semi-state funeral, which would be held in Kroonstad - probably on Friday.
President Thabo Mbeki conveyed his condolences to Schlebusch's family.
The role the state would play in the funeral would be released after consultation with the family, said presidential spokesperson Mukoni Ratshitanga.
Schlebusch served as vice president of the Republic between 1981 and 1984.
Former president FW de Klerk said in a tribute on Monday that Schlebusch played a "key role" in setting South Africa on the road to a new political dispensation.
He said that in political office, Schlebusch had excelled as "a man of integrity, honesty and balance".
"On a more personal level he was a good friend and at times a father figure during the development of my own political career. I always held him in the highest regard."
Schlebusch hailed from what was then the Orange Free State, where he served as mayor of Henneman in the 1940s.
He served as MP for Kroonstad from 1962 to 1980, wore the speaker's robe from 1974 to 1976, and also held the portfolios of minister of public works and immigration, and minister of justice and internal affairs.
In 1972 he headed the notorious Schlebusch Commission, which resulted in legislation that allowed the authorities to declare civil society organisations "affected".
This meant they could not receive foreign funding, and allowed the state to seize money they already had.
Among the organisations declared affected as a direct result of Schlebusch's recommendations were the National Union of South African Students and the Christian Institute, while the commission also attacked the South African Institute of Race Relations.
"The malign shadow of Schlebusch lingered to the end of the decade, when he warned the South African Council of Churches not to attack security legislation, concern itself with political detainees, or provide funds for political trials," wrote author Christopher Merrett in his 1995 book A Culture Of Censorship.
When PW Botha came to power in 1978, thanks in no small degree to Schlebusch's support as Free State leader of the party, he appointed Schlebusch to head a Cabinet committee to explore constitutional change.
In 1980 Schlebusch recommended abandoning the Westminster system and converting the Senate into a President's Council, made up of nominated whites, coloureds and Indians, as a think tank for ideas on a new constitutional dispensation.
The council, established under his leadership, was a first step towards the tricameral parliamentary system - a doomed attempt to co-opt coloureds and Indians into the system while excluding blacks.
Along with the leadership of the council, Schlebusch was made vice state president, a post he held from January 1981 to September 1984.
He was the only person ever to hold the title, which was scrapped when Botha became the country's first executive, rather than ceremonial, state president.
Subsequently he also briefly held the position under Botha of minister in the office of the president.
Former Rand Daily Mail journalist Benjamin Pogrund wrote in his 2000 memoir War Of Words that Schlebusch was admired by his fellow-Afrikaners for being a God-fearing man of integrity and honesty.
Asked by Pogrund at a private meeting in Cape Town in the early 1980s to describe National Party policy, Schlebusch replied: "If you want me to sum up our policy in one word then the word is compassion."
This, Pogrund pointed out, as the government's District Six removals were reaching their grim end little over a kilometre away.
"Yet there wasn't the slightest doubt that he believed it to be an honest statement and that is how he saw himself and his government's policies," Pogrund wrote.
Schlebusch's wife, also named Isabel, died in 1996.
He will be buried next to her in the graveyard of the Kroonstad North NG Church. - Sapa