It's worth quoting Mandela's response to the offer,
I am surprised at the conditions that the government wants to impose on me. I am not a violent man. My colleagues and I wrote in 1952 to Malan asking for a round table conference to find a solution to the problems of our country, but that was ignored. When Strijdom was in power, we made the same offer. Again it was ignored. When Verwoerdwas in power we asked for a national convention for all the people in South Africa to decide on their future. This, too, was in vain.
It was only then, when all other forms of resistance were no longer open to us, that we turned to armed struggle. Let Botha show that he is different to Malan, Strijdom and Verwoerd. Let him renounce violence. Let him say that he will dismantle apartheid. Let him unban the people's organisation, the African National Congress. Let him free all who have been imprisoned, banished or exiled for their opposition to apartheid. Let him guarantee free political activity so that people may decide who will govern them.
I cherish my own freedom dearly, but I care even more for your freedom. Too many have died since I went to prison. Too many have suffered for the love of freedom. I owe it to their widows, to their orphans, to their mothers and to their fathers who have grieved and wept for them. Not only I have suffered during these long, lonely, wasted years. I am not less life-loving than you are. But I cannot sell my birthright, nor am I prepared to sell the birthright of the people to be free. I am in prison as the representative of the people and of your organisation, the African National Congress, which was banned.
What freedom am I being offered while the organisation of the people remains banned? What freedom am I being offered when I may be arrested on a pass offence? What freedom am I being offered to live my life as a family with my dear wife who remains in banishment in Brandfort? What freedom am I being offered when I must ask for permission to live in an urban area? What freedom am I being offered when I need a stamp in my pass to seek work? What freedom am I being offered when my very South African citizenship is not respected?
Only free men can negotiate. Prisoners cannot enter into contracts. Herman Toivo ja Toivo, when freed, never gave any undertaking, nor was he called upon to do so. I cannot and will not give any undertaking at a time when I and you, the people, are not free. Your freedom and mine cannot be separated. I will return.