A powerful member of South Africa's ruling party on Wednesday accused the new government spokesman of making racially insensitive comments that echoed the injustices of the apartheid era.
The fallout could hurt President Jacob Zuma and his African National Congress who are facing local elections in May.
Economic Planning Minister Trevor Manuel, the former finance minister, said spokesman Jimmy Manyi brought shame to the dreams of Nelson Mandela and tarnished the non-racial policies of the ANC by making disparaging remarks in a television interview about a mixed-race group of people classified as coloureds.
I know who Nelson Mandela was talking about when he said from the dock that he had fought against white domination and he had fought against black domination, Manuel, himself coloured, said in an open letter quoted by the Star newspaper.
Jimmy, he was talking about fighting against people like you, the letter said.
Manuel was not available for comment and Manyi told the SAPA news agency he would not comment. His remarks were made in 2010 but sparked a national outcry after they were posted on YouTube last week.
The ANC has called Manyi's comments, made before he was appointed government spokesman last month but while he was a leading official in the Labour Ministry, unacceptable but has not asked him to step down.
Manyi, appointed to help Zuma's government prepare for the polls and push expensive job creation programmes, said in the television interview that there were too many coloureds in the Western Cape -- the area that includes Cape Town.
Manyi, speaking in his capacity as a government official and the president of the Black Management Forum, an organisation created to help non-white managers, said coloureds should spread in the rest of the country ... so they must stop this over-concentration situation because they are in over-supply where they are.
He then said the concentration in the Western Cape is not working out for them.
Coloureds -- descendants of the British, Portuguese, African tribes and others -- were forcibly concentrated in the western region under apartheid and have mostly remained there 17 years after the end of the racially oppressive system.
The ANC controls all of South Africa's nine provinces except the Western Cape, where coloureds have helped the opposition Democratic Alliance take control of local government.
Coloured South Africans constitute about 3 million of the country's 50 million population made up mostly of blacks. Whites make up around 5 million.
In his letter Manuel, respected for his role in the fight against apartheid, said Manyi, a black, had the same mind that operated under apartheid