Toyota will decide by the end of this month whether to pull out of the California plant it has operated with General Motors since 1984, a top executive said today.

The fate of the New United Motor Manufacturing Inc (NUMMI ) plant in Fremont has become a politically charged issue in the state, with lawmakers and Governor Arnold Schwarzenegger appealing to Japan’s top automaker to save the 24 year old plant and its 4,500 jobs.

GM pulled out of the joint venture in June leaving its share with Motors Liquidation, the entity that has taken over management of the ‘old GM’ assets left in bankruptcy.

A senior Toyota source told Reuters the Japanese carmaker would like to reach a decision by the end of this month. He added that, if Toyota decides to pull out, it would be up to NUMMI to decide how to proceed, including whether and how to liquidate the factory.

Toyota President Akio Toyoda told an automotive conference in Michigan earlier this week that he hoped to make a decision soon on whether to shutter the factory.