Former Finance Minister Trevor Manuel's comments that business leaders were cowards were "unwarranted", the South African Chamber of Commerce and Industry (Sacci) said on Friday.

"The description by Minister Manuel of business as cowards at the WEF [World Economic Forum] was unwarranted," said the chamber's chief executive, Neren Rau.

"Business often acts to preserve the integrity of our business environment and is sometimes forced to make substantial compromises to safeguard positive investor perception."

The website fin24 reported on Friday that Manuel, who is now the head of the National Planning Commission in the Presidency, criticised both business and union leaders in an address at the WEF meeting in Cape Town this week.

His audience included Sasol CE Pat Davies and Old Mutual MD Paul Hanratty.

Manuel seemed to indicate that labour unions were too powerful, the website reported.

"There is no counterweight in society if you have cowards in business," Manuel said.

"You have to have counterweights or you don't make progress.

"You don't have to keel over every time someone stands up and says 'I disagree'," he added.

Rau said he agreed with Manuel in that strikes were too often used as an instrument of influence.

This caused "substantial harm" to business and the perception of investors about the local business environment, said Rau.

"In a society where economic outcomes are determined in negotiations between business, government and labour, business has been a highly successful counterweight in the face of an alliance between government and labour."

Davies, of Sasol, argued during the discussion with Manuel that sometimes the public did not know what went on behind the scenes.

Most of the times when business leaders gave in to union demands, it was upon request from the government, said Davies.

"I have had Cabinet Ministers phoning me to pressure me into solving these issues," said Davies, adding that "you have to pick your battle ground".

South Africa's largest trade union on Friday also slammed Manuel's comments.

"The National Union of Mineworkers (NUM) is disappointed that such bile could come from one of the most senior ministers in government," said the NUM in a statement.

The NUM said Manuel's comments were "dishonest", "unfortunate" and "irresponsible".

"His utterances are unfortunate given the imbalance that exists between the employee and employer parties...

"It is totally irresponsible for Manuel to suggest a 'counterweight' when there is a glaring imbalance in favour of business," the NUM said.

Manuel also said unions were using Section 77 of the Labour Relations Act too easily, referring to the Western Cape branch of the Congress of South African Trade Unions (Coastu) using this to take on Premier Helen Zille's all-male executive council.

The provincial Cosatu branch has taken the issue to the National Economic Development and Labour Council under the Section 77 provision.

"If you use this weapon too often you blunt it. The socio-economic strike is a blunt axe. It's useless," said Manuel.

The NUM said it would "continue to flex its muscles so that the blue-collar worker is listened to and gets what he bargains for".

"The NUM has in the past undertaken strike action in pursuit of safety in the mines and would do it in the future," the union said.