4 March 1990
The release of Nelson Mandela on 11 February 1990 was a catalyst that sped up the change in the political dispensation in South Africa. On 4 March 1990 343 political prisoners on Robben Island went on a hunger strike demanding their release in order to strengthen the bargaining positions of the ANC. While de Klerk suggested that the unconditional release of political prisoners was a real possibility, he faced considerable opposition from the white electorate as many of the political prisoners were detained for their involvement in acts of violence. Nonetheless, this campaign showed a rare glimpse of political unity among Black political prisoners opposed to Apartheid, as prisoners from political movements across the political spectrum joined in this hunger strike for demanding their release.
References

New York Times,"South African Political Prisoners Fasting",From: New York Times,[Online],Available at: www.nytimes.com,[Accessed on:05 February 2014]|CSVR,Savage.k.,"Negotiating the Release of Political Prisoners in South Africa",From: CSVR,[Online],Available at: www.csvr.org.za,[Accessed on:05 February 2014]