South African energy workers plan to strike from Thursday over wages, potentially affecting crude oil refineries and fuel depots, the Chemical, Energy, Paper, Printing, Wood and Allied Workers Union (CEPPWAWU) said on Wednesday.
Around 23,000 workers in the petrochemical and pharmaceutical sectors are expected to down tools, Clement Chitja, head of collective bargaining, said.
"We want a deal of 9 percent in one year," Chitja told Reuters, adding that employer associations were offering less and looking for multi-year agreements.
The National Petroleum Employers Association was not available to comment.
The work stoppage could further damage the economy, which is forecast by the central bank to remain stagnant this year after expanding 1.3 percent in 2015.
Africa's most industrialised economy is a net importer of refined petroleum products and a prolonged strike could lead to shortages ahead of municipal elections in August.
Shell and BP jointly operate South Africa's largest refinery, the 190,000 barrel a day Sapref plant along the east coast, with Chevron, Sasol and PetroSA also running refineries.
(Reporting by Wendell Roelf; Editing by Joe Brock)