12 April 1991
On 12 April 1991, the African National Congress (ANC) made public its proposed constitutional principles in a discussion document, which to some extent had the effect of shifting public focus away from the prospect of a total breakdown. Among the things that the discussion document called for was a non-racial democratic state with a Bill of Rights, the independence of judiciary and other related issues. This was followed by the first plenary session of the Convention for a Democratic South Africa (CODESA), which began on 21 December 1991 at the World Trade Centre, Johannesburg.
References

South Africa History Online,‘Chapter 5 - Preparing to negotiate’, From: South African History Online,[online], Available at: www.sahistory.org.za [Accessed: 14 March 2012]|South Africa History Online, ‘The CODESA negotiations’,Form: South African History Online,[online], Available at www.sahistory.org.za [Accessed: 14 March 2012]