About 2,000 union members marched on the grounds of General Motors on Thursday to support auto industry workers in their fight against a decision by the company to shut down their truck plant in Oshawa, Ont.

The rally began at noon at GM's Canadian headquarters in Oshawa. Several unions across the province were bused in to join members of the Canadian Auto Workers union at the rally in a show of solidarity.

The demonstration was peaceful as protesters made their way along Park Road to Bloor Street and then turned around again. The rally ended with speeches by union officials.

The event was the latest step in a week full of protests by GM workers.

Employees have formed a blockade at nearby truck plant since last Wednesday, after GM announced rising fuel costs were forcing them to cut production on their trucks and SUVs.

Just two weeks after reaching a tentative contract agreement with CAW, GM announced they would be closing down the Oshawa plant, effectively laying off 2,600 people.

Union officials accused GM of being sneaky by not mentioning the closure during the collective bargaining process.

Keith Osborne, with CAW Local 222, told CTV Toronto before the rally began that the purpose of the demonstration is to send corporations a message about bargaining in bad faith.

"When you negotiate a collective agreement with a corporation they have to live up to it for three years and the union is expected to live up to it," he said.

"The other issue is fair trade, free trade. Corporations can't be allowed to take work that we do and take it to third world countries, places like Mexico, and pay (Mexican workers) $4.50 an hour."

Chris Buckley, president of Local 222, spent the morning in court fighting a legal injunction to end the blockade. However, he took a break to come and speak to the crowd at the rally.

He told workers the union would not stop fighting to keep their jobs, and he also urged the government to take action.

"The bigger fight is for the bleeding of good-paying Canadian jobs," he said to a cheering crowd. "We're not going to stop until we force the government to wake up. The bleeding must stop."

Injunction decision coming Friday

While the rally was going on, lawyers for GM were in court seeking a legal injunction to end the blockade of their property by union members.

The court heard testimony from a lead negotiator for GM who said the union wasn't given advance notice of the plant closure.

However, she said the closure was based on market demand and that CAW was told that any decision on the plant's future would be based on the market.

The negotiator also said GM couldn't keep making trucks if the public wasn't interested in buying them.

Buckley also testified during the proceeding, telling court GM acted in bad faith when it came to a collective agreement with the union on May 16 and failed to mention their plan. The decision to close the plant was made public on June 2.

After hearing testimony throughout the day, the judge reserved a decision until Friday.

Buckley has said if the injunction was granted, the union would simply move their protest to another location.

GM has also filed a suit against the union seeking $1.5 million in compensation for lost revenue during the demonstration.

With reports from CTV Toronto's Dana Levenson and John Musselman