The Constitution must be reviewed to allow for expropriation of land without compensation, National Union of Metalworkers of SA (Numsa) general secretary Irvin Jim said on Tuesday.
"We are very firm that section 25 of the Constitution is a problem. Our government cannot do anything, it cannot break the back of white monopoly capital that has become an enclave swimming in... wealth that was not redistributed," he said.
"On the issue of land we are unanimous in the belief that the land must be returned to the people of the country in accordance with the Freedom Charter and that expropriation without compensation must be complemented by abolishing the principle of 'willing buyer-willing seller'."
Jim was talking to reporters in Johannesburg, after Numsa held its ninth national congress in Durban last week.
He said the union agreed it would assist the African National Congress, if it chose to review the Constitution.
"If the ANC takes a decision from both its policy and national conference and says it wants to review the Constitution, our people will vote for the African National Congress. We will deliver more than two-thirds [in the National Assembly]."
He said section 25, which deals with property rights, was used by "white capitalists" to ensure that they would continue to own the country's means of production and its wealth.
"We are not narrowly pursuing another race [situation]. We think that equal access to the economy of this country is in the best interests of both black and white," Jim said.
"Unless both blacks and whites have equal access to the wealth this country has, the country is going nowhere."