Government spokesman Jimmy Manyi says he will not comment on an open letter by Minister in the Presidency Trevor Manuel in which he was labelled a "racist".

"I'm not going to say a word. Not a word," Manyi said.

In the open letter, which was published in the Mercury newspaper, Manuel hit out at Manyi over his comments on coloured people.

"I want to draw your attention to the fact that your statements about 'an over-concentration of coloureds' are against the letter and spirit of the South African constitution, as well as being against the values espoused by the Black Management Forum since its  inception," Manuel wrote in the letter.

"I want to put it to you that these statements would make you a racist in the mould of HF Verwoed [Hendrik Verwoed, former SA prime  minister, dubbed the "architect of apartheid"]."    

Manyi, then the director-general of labour, said in a show broadcast on KykNet's Robinson Regstreeks in March 2010 that there was an "over supply" of coloureds in the Western Cape.

The ANC distanced itself from Manyi's remarks, saying they were "disturbing" and "unacceptable".

Government Communication and Information System (GCIS) deputy chief executive officer Vusi Mona had since apologised for the remarks on Manyi's behalf.

Manuel wrote that the fact that Mona had issued an apology for Manyi's remarks showed "...that you [Manyi] lack the moral conviction to publicly apologise says so much about your acute lack  of judgement".

 "Mr Manyi, you may be black, or perhaps you aren't, because you do not accept that label and would prefer to be 'only a Xhosa', whatever the label you choose, I want to put it to you that your behaviour is the worst-order racist."    

Manuel said that because of Manyi's comments government was being asked to explain what "was in the mind" of drafters of the amendments to the Employment Equity Bill.

"Now, in the light of the utterances you have made at a time when you were the DG of the department of labour, and given the fact that the amendments to the Employment Equity Act were drafted during your tenure, I have a sense that your racism has infiltrated  the highest echelons of the government."

Manuel pointed out to Manyi that the "coloureds" were the sons and daughters of those who had fought anti-colonial battles and made huge sacrifices in the struggle against apartheid.

"By the way, what did you do in the war, Jimmy?" he asked.

Manuel ended off the letter with: "I know now who Nelson Mandela  was talking about when he said from the dock that he had fought against white domination and that he had fought against black domination. Jimmy, he was talking about fighting against people like you."

• WHY NOW?
  Manyi's remarks were made in 2010 but sparked a national outcry after they were posted on YouTube last week.