Germany's largest industrial labor union, IG Metall, called for a concerted day of action against what it says are unacceptable measures to cut costs at one of the country's biggest corporations.

Some 600 workers at a Mercedes plant in Düsseldorf kicked off the action with an overnight demonstration by torchlight through the city streets.

At DaimlerChrysler's main site in Sindelfingen, near Stuttgart in southern Germany, around 20,00 employees answered the call to strike and stopped work for two hours earlier in the morning.

Further stoppages have been staged at car and truck factories throughout the country during the course of the day, notably in Berlin, Bremen and Hamburg, said IG Metall and the employee's council.

The carmaker employs around 160,000 people in Germany and some reports suggest that as much as half the workforce could join in the protests.

"It's war"

The strikes at all the German Mercedes factories are a direct response to DaimlerChrysler's threats to shift production of its new Mercedes C-Class sedan away from Sindelfingen to South Africa if unions do not agree to €500 million ($615 million) in personnel cost costs. Such a move could result in the loss of 6,000 jobs in Sindelfingen.

IG Metall slammed the threat as "blackmail" and vowed to fight the company's plans.

Protestors in Sindelfingen, a factory which employs close to 30,000 people, rallied around the union and displayed signs crying out, "it's war."

The head of the employee's council in Sindelfingen, Erich Klemm, said the union was willing to offer pay reductions up to €180 million, but not management's "outrageous" demands for half a billion in reductions.

A climate of fear

DaimlerChrysler has also threatened to move some jobs from Sindelfingen to Bremen, where production costs are lower, and to change contracts to eliminate extra pay for late shifts and five-minute breaks on every hour, effectively leading to an increase of the work week without more pay.

"Such proposals make me sick," said Klemm, who vowed that all the Mercedes factories would stick together in a show of solidarity.

The president of Germany's parliament, Wolfgang Thierse, lashed out at DaimlerChrysler management for "creating a climate of fear."

"It's repulsive to exert pressure on employees by making ultimatums," he told the daily Tagesspiegel on Thursday.