ST. PETERSBURG, May 15 (RIA Novosti) - Some 150 workers from a Ford car factory near St. Petersburg held a protest rally on Friday against a four-day working week at the plant, a RIA Novosti correspondent reported.

The workers say that the management of plant, located in the Leningrad Region town of Vsevolozhsk, has introduced a four-day working week, but increased the daily output plan. As a result, workers have lost 15% of their salaries, while the total output of cars has remained at almost the same level.

The protestors also demand further development in the plant's social support strategy, in particular, better healthcare.

The workers called on the regional government to participate in talks on the issue.

The trade union's head, Alexei Etmanov, said that the rally was unlikely to be the last and that the workers were prepared to stand up for their rights.

The Ford plant, which opened in the summer of 2002, produces Ford Focus cars and employs more than 2,000 people.

Some 1,000 employees halted production on November 20, 2007, demanding a 30% pay rise. The strike ended when management agreed with the union to increase wages by up to 21%. In September 2008 a further 8%-10% wage increase was agreed. The halt cost the plant 4.5 million rubles ($125,600).

The plant's management filed a compensation claim against the workers, but it was rejected.

The strike was heralded by many Russian social commentators as the birth of organized union activity in post-Soviet Russia.

Late last year, Etmanov was twice attacked by a group of men, but managed to escape both times without serious injury. He said that after the first incident that he had received a telephone call telling him to cease union activities.