Mr. Oliver Tambo, the President of the African National Congress, yesterday rejected suggestions that his organisation should abandon the use of violence in response to Pretoria's partial reforms, and called instead for a "final push" to force an end to apartheid.
"The South Africans would call it a total onslaught," he said in London yesterday. "The armed struggle is part of our struggle and must be part of this push."
The ANC's refusal to renounce violence has cost it support among white liberal opinion in South Africa and led Mrs. Thatcher to call it a terrorist organisation. After abolishing many of the restrictions most resented by South African blacks, Pretoria hoped for a reduction in violence.
But Mr. Tambo replied: "We know of no precedent where there was a unilateral cessation of hostilities before negotiations were started. Who has been waging armed struggle against us since 1948? We cannot be going bare-breasted in this situation."
But Mr. Tambo said the increased violence would not involve indiscriminate killing. "We ought to be very careful about where we explode bombs, and 99 percent of the time we are. It is known that we have weapons and (one might think) that we would be going into houses shooting people.
"We don't (do so), because we are guided by certain principles. Our struggle must not be reckless, it must not be uncontrolled, but we must influence a situation which brings closer the collapse of the regime.
"I think that if the situation got ugly enough, there would be very strong (white) pressure on the government to talk to the ANC."
He was asked about remarks made by leaders of the ANC's military wing, Umkhonto we Sizwe (Spear of the Nation) in an interview with The Times last week. They wanted to take the war more visibly to the white community.
Mr. Tambo replied: "I cannot imagine anyone is saying that we should go shooting our way into white suburbs and killing whites because they are whites. But if, for example... we attack police stations which are in white suburbs, that would draw the attention of the white community to what is happening."
He said the ANC did not regard ordinary whites as soldiers even if they and their families kept guns at home and were trained to use them. One of the main aims of the offensive, he said, was "to persuade the whites that this should be a perpetually worsening crisis".
But Mr. Tambo made it clear that he thought it would take a combination of heightened conflict and an increase in international trade sanctions to make Pretoria seek talks with the ANC. The obstacle was Mrs. Thatcher's refusal to accept further sanctions. "She has been so firm and so solid and everything (she has said) has operated to protect South Africa. If she moved... everything would move," he said.
Mr. Tambo's remarks came at the end of a week in which the ANC has used the 70th birthday of its imprisoned leader, Nelson Mandela, to launch an unusually successful information offensive in Britain and other countries.
But in South Africa itself the black leader who has achieved the most publicity in calling for Mr. Mandela's release has been Chief Mangosuthu Buthelezi, president of the Zulu Inkatha movement and Chief Minister of KwaZulu.
Relations between them have long been uneasy, but yesterday Mr. Tambo attacked him in unusually strong terms. "He has allowed himself to be used by the regime in a remarkable way. He says all the things that they say, he takes all the positions they are taking, which leads the majority of our people to see him as something apart. He started very well... but then it drifted, and he has become very remote now." He said that the split followed a meeting between the two men in London, although it had appeared to go well at the time. He compared Chief Buthelezi with Bishop Abel Muzorewa, who served as Prime Minister of Zimbabwe-Rhodesia in 1979.
"From the London meeting he (Chief Buthelezi) went off at a tangent and has never turned back and has become very useful to the regime and may have been seen by the regime as a future Muzorewa," he said. "He continues to say he is opposed to apartheid...(and yet) he continues to make speeches against the ANC."
Mr. Tambo also spoke of a split between the Foreign Office and Downing Street on the Government's attitude towards the ANC.
Asked about Mrs. Thatcher's comment at a press conference at the Commonwealth Heads of Government Conference in Vancouver last October that the ANC was a terrorist organisation comparable with the IRA, he said: "I don't think that the Foreign Office shares common ground with the Prime Minister on the question of who and what the ANC is."
He hoped she was speaking off the cuff, and questioned whether she would repeat the remark now.
He has met Sir Geoffrey Howe, the Foreign Secretary, and Mrs. Lynda Chalker, the Minister of State at the Foreign Office, but not Mrs. Thatcher. She said the Government would not talk to the ANC and that when Sir Geoffrey did so he was acting in his capacity as president of the European Community. But Mr. Tambo said: "I was meeting Sir Geoffrey Howe, the British Foreign Secretary; I was not interested in what suit he was wearing."