The state-owned Transnet was already operating below capacity because of a shortage of locomotives, poor maintenance, vandalism and theft of its infrastructure, which has cost miners billions of rand in potential revenue because of delays to mineral shipments.

The United National Transport Union (UNTU) and the South African Transport and Allied Workers’ Union (SATAWU), which together represent most Transnet workers, this week turned down Transnet’s offer of a wage rise of 3%-4%, saying it was below South Africa’s annual inflation rate, which was 7.6% in August.

UNTU said its members began a strike on Thursday and SATAWU said it will join in the strike from Monday.

“This will have a profound impact on economic activity across all sectors, and (Transnet) urges workers to consider the long-term consequences of the strike on themselves, their colleagues, their families and the South African economy as a whole,” Transnet said in a statement.

Transnet, which operates all of freight rail and port operations in Africa’s most advanced economy, said the strike was illegal and that unions had not followed rules set down in the labour law.

It also questioned the balloting processes used to approve the strike action and said no picketing rules had been agreed by the company and striking workers, as required by the labour law, the unions said.

UNTU and SATAWU said Transnet’s lawyers had written to them on Oct. 3, saying their industrial action would be illegal as some workers involved provided essential services and were restricted from striking.

Both unions rejected Transnet’s charges, saying they had given the required 48-hour strike notice and engaged Transnet on picketing rules.

UNTU general secretary Cobus van Vuuren accused Transnet of seeking to intimidate workers by declaring the strike illegal.

“This is just another attempt by Transnet to deploy scare tactics to prevent the strike and to delay the process,” he said.

All parties have agreed to mediation by the Commission for Conciliation, Mediation and Arbitration (CCMA), a state agency. The unions have said further talks, due to start on Oct. 12, will not affect strike plans. DM/Reuters

(Reporting by Kopano Gumbi and Nelson Banya; Editing by Edmund Blair and Barbara Lewis)