Thousands of workers at a General Motors factory in Brazil went on strike Friday in protest of the planned furlough and the firing of close to 800 staff members.

According to the Wall Street Journal nearly 5,200 workers covered by the Metalworkers Union in Sao Jose dos Campos went on strike, halting production.

The union said workers had voted for an indefinite strike because of GM's plans to lay off almost 800 staffers in April.

GM said the local union is required by law to communicate planned strikes and protests to the company. They said no such communication occurred.

"GM is taking appropriate legal action and asked employees to return to work immediately," the company said in a statement. "A conciliation hearing is scheduled in the Regional Labor Court on Tuesday."

Union officials say the automaker gave workers an ultimatum. They were to either accept temporary layoffs or the company would impose job cuts. This ultimatum comes even after the union and the company came to an agreement last August to keep the nearly 800 workers until at least the second half of this year. 

"The workers reject the GM proposal. There is no guarantee of the jobs being saved," union general secretary Luiz Carlos Prastes said.

The factory's staff produces the S10 and Trailblazer models.

In 2012, the union conducted a 24-hour strike to protest a reduction in output. The union and the company had butted heads previously when GM trimmed its payrolls at the local plant from about 7,500 workers in 2012 to about 5,200 currently.

The auto industry in Brazil, the world's fifth largest, has fallen on hard times. Last month, Volkswagen canceled plans to slash 800 of 13,000 jobs at their plant in Anchieta, near Sao Paolo, after a 10-day strike.

Volkswagen said the layoffs were justified as the country had faced two years of poor growth, taking a heavy toll on the company. Production dropped 15 percent in 2013.

Brazil's auto dealership association Fenabrave noted a sales slide of 7.15 percent last year to 3.5 million units, the worst showing in five years.