TORONTO (Reuters) - Canadian autoworkers on Saturday stepped up protests against plans to close a General Motors (GM.N) truck plant in Oshawa, Ontario.
They drove hundreds of cars slowly around the factory in an action they said disrupted parts deliveries and briefly shut down production.
A spokesman for the Canadian Auto Workers, which has staged a four-day blockade of the General Motors of Canada headquarters in Oshawa, said the convoy was "a second phase" that marked an escalation of the union's strategy to win a reversal of GM's decision to close the plant next year.
Since GM this week said it would close four truck plants in North America, workers have blocked a road leading GM Canada's headquarters in Oshawa, about 40 miles east of Toronto, preventing office workers from getting to their jobs.
CAW spokesman Keith Osborne said the convoy lasted about three hours and involved about 250 cars.
He said it slowed traffic enough to prevent trucks from getting through the plant's main gate to deliver parts, leading GM to shut production lines briefly at the truck plant and a nearby car plant.
Osborne said it was not the union's intention to disrupt GM's operations.
"We're doing this to get information out, to show solidarity, to show GM that they can't violate our contract," he said.
A GM spokesman could not by reached immediately to confirm whether production was stopped or to comment on the union's actions.
The truck plant, which makes the Chevrolet Silverado and GMC Sierra, employs about 2,600 hourly workers. It is one of the four North American plants that GM said it will close to cut capacity and shift production toward more fuel-efficient cars as record gasoline prices depress truck sales.
Osborne told CBC television that until Saturday the union never touched production.
"This is us actually coming out to the worksite," he said, referring to the union's expansion of the protests beyond the blockade of the headquarters.
Osborne said union leaders were planning to meet later on Saturday to decide on "phase 3" of the protests. He declined to be more specific.
CAW President Buzz Hargrove on Friday held a 90-minute meeting in Detroit with senior company executives, including Chief Executive Rick Wagoner. Afterward he said he was very disappointed because GM showed no sign of considering a reversal of the decision to shut the Oshawa truck plant.
Hargrove said the union may challenge GM in court.
GM, which has seen its U.S. sales drop 16 percent this year, is also looking to sell its Hummer SUV line.
The automaker said it was forced to take the drastic steps, which echo moves taken by Ford Motor Co (F.N), because of signs that the record-high pump prices had driven U.S. consumers away from trucks and SUVs for good.
Hargrove and union officials have accused GM of violating the terms of a just-completed three-year labor contract they say obliges GM to keep the Oshawa truck plant open until 2011.
GM Canada spokesman Stew Low said GM had begun talking to the CAW this week about bringing a third car model to the "flex" line in its Oshawa car plant.
That production line, which will begin making the Chevrolet Camaro this year, was already set to get a second car model as part of the recent deal with the CAW.
Low on Friday said GM planned no legal action against CAW workers who have blockaded the company's head office. About 1,000 GM salaried workers were still working from home or in plant or hotel meeting rooms as of Friday, he said.
Additional reporting by Kevin Krolicki and Soyoung Kim in Detroit, and John McCrank in Toronto; Editing by Xavier Briand