A Venezuelan court last week ordered the seizure of the company's Valencia plant, ruling in favor of two dealers that had filed a case in 2000 against the subsidiary on grounds they had not complied with an agreed sale of 10,000 vehicles.
Workers say that before the seizure was announced, GM had been dismantling the plant, which has not produced a car since the beginning of 2016 because of shortages of parts and strict currency controls in the OPEC nation.
The seizure, which GM called "illegal," comes amid a deepening economic and social crisis in leftist-led Venezuela that has already roiled many US companies.
"We all received a payment and a text message," said a worker who had worked for the company for more than a decade, adding that his corporate email account had been deactivated over the weekend.
"Our former bosses told us the executives left and we were all fired. There is no longer anyone in the country," added another employee who received the same message on his personal cell phone and a payment to his account. He had been at GM for five years.
The company did not immediately respond to a request for comment about the layoffs or the worker allegations it had already been dismantling the plant.
GM said last week that it was halting operations and laying off workers due to the "illegal judicial seizure of its assets."
'SHOW YOUR FACE'
The leftist government of Nicolas Maduro says it is not seeking to expropriate the plant, which has been operating for 35 years, and has called on GM to come back.
"To the current General Motors president of Venezuela, Jose Cavaileri: You come here, show your face and share with us the options to restore normality," said Labor Minister Francisco Torrealba said Monday.
GM is not the first company to fire Venezuela employees by text message. Clorox did the same two years ago when announcing its exit from the crisis-struck country, after which workers took over the plant.
GM's plant closure comes after Venezuela's automobile production fell in 2016 to a record low of eight cars per day, according to a local automotive group.
Two union spokespeople said they had no official company information on the layoffs, but said that most workers received the messages along with a bank deposit.
Neither employee would reveal the amount they received but union leaders said it was too low.
(By Corina Pons Writing by Girish Gupta; Editing by Alexandra Ulmer and Nick Zieminski)