Johannesburg - South Africa's metalworkers union on Thursday reiterated a threat to strike from next month in the metal and engineering industries, a move that could cripple production in the auto industry for a second straight year.

Officials from the National Union of Metalworkers South Africa (NUMSA) told reporters they “might” strike for higher wages from July 1.

The union, which represents 220,000 workers, last year brought auto production - which represents around 6 percent of economic output - to a standstill with a four-week walk-out at parts manufacturers.

A further increase in labour unrest could be disastrous for Africa's most developed economy.

Platinum workers have been on strike for five months with no immediate end in sight.

The strike pushed the economy into contraction in the first quarter.

The main union in the platinum industry has rejected a government-brokered wage increase proposal, a local business newspaper reported on Thursday. - Reuters