Toyota is reportedly prepared to make an announcement as soon as this Friday.

California state legislators in Sacramento are planning to introduce a resolution calling on Toyota to keep open the New United Motor Manufacturing Inc. plant in Fremont.

The legislation is being marked as a legislative priority and supporters are hoping to have it adopted before Toyota makes any kind of announcement about the fate of the plant, which employs 5,300 workers.

Toyota is reportedly prepared to make an announcement as soon as this Friday, setting out a timetable for closing the factory, which is last auto plant on the West Coast.

“We’re still trying to be optimistic,” said Tracy Rosen, a spokeswoman for “Friends of NUMMI,” which is described as a group of families, workers, suppliers and local businesses from throughout the state of California. The group is trying to persuade Toyota and the newly reorganized General Motors Company to consider the total loss in jobs, the impact on suppliers, local businesses and families that will be devastated by the plant’s impending closure.

The group estimates more than 50,000 jobs in California are now connected to the NUMMI plant and its shutdown will have a huge impact on the state’s distressed economy, which already has double-digit employment rates.

In addition, the closure will lead to substantial losses in local and state revenues and employment taxes; it will increase property foreclosures, which will lead to a drop in attendance in local schools due to affected families requiring relocation, and significantly increase the unemployment claims – developments that California’s struggling economy can’t afford, Friends of NUMMI said in a statement.

Up until now, Toyota has never closed a factory in the U.S. or abroad. But the company’s long-standing commitment to a stable employment has been challenged by the heavy losses the company has sustained over the last 15 months.

The Japanese auto giant has even taken to shutting down elevators in buildings in Japan to save money.

The cost of the shutdown, if approved by Toyota’s board, could easily run into the hundreds of millions of dollars and virtually all of the cost will have to be borne by Toyota because the “old” GM that own a 50% share of  NUMMI is bankrupt, with its share due to be sold if a buyer can be found.

Meanwhile, California continues to be Toyota’s largest market for auto sales and the opposition to the shutdown has picked up support across the state, Friends of NUMMI said.

NUMMI started as the pioneering joint venture of General Motors Corporation and Toyota Motor Corporation. NUMMI helped change the automobile industry by introducing the Toyota Production System and a teamwork-based working environment to the United States under a UAW contract.