South Africa’s mainly white Solidarity union has given Sasol a 48-hour notice to strike over the energy giant’s plan to launch a share ownership scheme exclusively for black staff, the union said on Tuesday.

Sasol plans to sell 25% of its local operations to mainly qualifying black employees in R21 billion ($1.58billion) deal that would be vendor-financed by the company.

The world leader in the technology that converts coal and gas to fuel has previously defended the scheme, saying it was not a company benefit but one that was specifically designed to address Sasol’s ownership component under South Africa’s black economic empowerment rules.

Under black economic empowerment rules, South African companies are required to meet quotas on black ownership,employment and procurement as part of a drive to reverse decades of exclusion under apartheid.

The union said a majority of its members had voted strike notice, but said the strike notice did not necessarily mean that it would hold the industrial action after 48 hours.

It said the scheme excluded white staff and foreign nationals.

“This type of crude racial exclusion cannot be tolerated any longer. These white workers are also valuable,” Solidarity Chief Executive Dirk Hermann said in a statement.

A Sasol spokesperson could not be reached for comment.

Shares in Sasol were little changed at 5,554.67 rand as of 1020 GMT.