RUESSELSHEIM, Germany (AFP)--Several thousand Opel car workers took to the streets Thursday as part of Europe-wide protests against cutbacks by General Motors Corp. (GM).

Organizers said between 15,000 and 18,000 people took part in a rally at Opel's main German plant at Ruesselsheim, near Frankfurt, carrying banners proclaiming "Yes we can" and "Fighting back makes the difference."

"Opel must live," Foreign Minister Frank-Walter Steinmeier told the demonstrators, fearful for their livelihood as the beleaguered U.S. parent company bids to slash thousands of jobs across Europe.

Steinmeier, a Social Democrat who will challenge Chancellor Angela Merkel in legislative elections in September, added: "Opel is not just about cars, it is about the people who go to the factory every day."

He said it was "unacceptable" and "disgraceful" that GM wasn't safeguarding their jobs.

Peter Giesser, a member of Opel's works council, said rallies were also expected at GM plants in Spain, the U.K., Belgium and Poland.

In Sweden, employees at Saab AB (SAAB-B.SK), another GM subsidiary, were to stage a rally in the southwestern city of Trollhattan, location of Saab's main Swedish plant with 3,700 workers.

A works council member at an Austrian GM subsidiary, which employs 1,850 workers at a site near Vienna, called for a "European rescue plan" for GM companies, a call echoed by Steinmeier.

GM, which is still threatened with bankruptcy and Thursday announced a $9.6 billion loss in the fourth quarter, has drawn up a European restructuring plan that would eliminate thousands of jobs.

The U.S. firm has also said it wants to get rid of Saab, which benefits from a Swedish court ruling that has helped it to avoid going under.

As for Opel, GM is mulling partnerships with outside investors or selling off stakes to keep the company going. In each case, the U.S. group has appealed to public authorities in Europe for aid.

The demonstrators called for Opel to split from its parent company, carrying banners saying, "better without GM."

Opel is set to hold a crunch meeting Friday to debate a restructuring plan, which German authorities have said is a prerequisite for talks over aid.

Germany's Economy Minister Karl-Theodor zu Guttenberg told a news conference he plans to speak to German regional leaders on Saturday about Opel's plight.

At the end of 2007, GM Europe employed more than 55,000 people, primarily in Belgium, the U.K., Germany, Poland, Spain, and Sweden.