The National Union of Metalworkers of South Africa (NUMSA) said on Monday it is considering a nationwide strike if its current talks with employers over wage increases failed.

The strike would probably start at the beginning of next month, NUMSA officials said.

The strike would further hit South Africa's economy at a time when the country's gross domestic product (GDP) slipped by 0.6 percent in the first quarter of this year, the first quarterly contraction since the recession in 2009.

A 19-week strike at the platinum sector was believed to be one of the major contributors to the decline.

The looming strike by NUMSA would involve almost 200,000 workers, much larger than the platinum strike that involves about 80,000 mineworkers.

NUMSA wants wages raised by 15 percent, while employers want to raise them by only 6.1 percent.

The lowest-paid members of the unions make around 4,000 rand (about 380 U.S. dollars) a month.

Economists have voiced concerns that South Africa's economy will not survive another long standing strike.

NUMSA is the biggest metal workers trade union in South Africa.