South Africa's metal workers' union Thursday said it is taking the local arm of General Motors Corp. (GM) to the country's Labour Court to force it to rehire workers laid off since April.

The National Union of Metalworkers of South Africa said it also wanted a moratorium on any further cuts and warned other car companies including Ford Motor Co. (F) and Volkswagen AG (VOW.XE) against what it said was similar "unilateral" action and a "psychopathic attitude to workers."

GM South Africa early this month said it wouldn't be affected by the bankruptcy filing of its parent company, but the union said the firm has since announced it will season manufacturing its Hummer vehicles in Port Elizabeth.

GM South Africa has cut more than 1,300 jobs since 2007, the union said.

"Reasonably, we are starting in the Labour Court of Johannesburg today (Thursday) to seek relief," NUMSA said.

-By Robb M. Stewart, Dow Jones Newswires; +27 11 783 7848; robb.stewart@dowjones.com