The Employment Equity Amendment Act aimed at increasing the employment of black people in South Africa has enraged businesses and liberals who say the legislation could see qualified workers lose their jobs.
The Democratic Alliance (DA), is to take to the streets in Cape Town on Wednesday to protest what it has dubbed the "race quotas" bill.
"Estimates show that... 600,000 people will lose their jobs because they have the 'wrong' skin colour or live and work in the 'wrong' areas," DA leader John Steenhuisen said in a statement.
Three decades after the end of apartheid, South Africa remains the world's most unequal country, according to the World Bank.
Almost one in two black South Africans were unemployed in the first three months of 2023, while the jobless rate was only 9.5 percent among white people, according to official figures.
The new law requires companies with more than 50 employees to submit equity plans reflecting the demography of the region they operate in and set out how they intend to achieve them.
It also allows for the Labour Minister to set numerical targets for specific economic sectors.
Gareth Ackerman, chairman of Pick n Pay, one of South Africa's largest grocery retailers, said the bill threatened private employers whose workforce does not mirror racial demographics.
"This would have the effect of making large numbers of qualified people unemployed and substituting them with unqualified people," he said in a statement this month.
The government has rebuffed criticism saying the law seeks to promote diversity and equality.
"It does not mean that the white people are going to be removed in order to create space for the disadvantaged groups," Labour Minister Thulas Nxesi told a broadcaster.
South Africa's largest trade union said the controversy surrounding the bill was overblown.
"It is a rational bill and not this big monster the DA is making it to be," Cosatu's spokesman Matthew Parks said.
White people account for less than 10 percent of South Africa's population but hold more than 60 percent of top management roles according to a recent study, he said.
About 90 percent of the country's 60 million people are black.
The bill, which amends pre-existing legislation, was signed into law by President Cyril Ramaphosa in April and is expected to enter into force in the coming months.
The DA has taken legal action to have parts of it struck down arguing it violates South Africa's constitutional principle of non-racialism.