A truck drives out of the blockade at General Motors Canadian headquarters in Oshawa, Ont., on June 7. (Aaron Harris/Canadian Press)

The Canadian Auto Workers (CAW) union isn't considering a strike over the decision by General Motors to close the truck plant in Oshawa, Ont., president Buzz Hargrove said Sunday.

The prospect of a wildcat strike had been rumoured as an option in the union's campaign to keep the plant open, and save the 2,900 jobs there. GM said on June 3 that it will close the plant in 2009, citing collapsing sales for the large pickup trucks assembled in the factory.

The union is considering its legal options, Hargrove said. "What's our best approach? Is it through the grievance procedure? Expedited arbitration, which we have under our contract? Is it the Ontario Labour Relations Board, or is it the courts? We'll decide which place we can be the most effective and get a decision the quickest before this thing starts to wind down."

The CAW has said GM broke the union contract but analysts have said the company used a loophole in the contract to close the plant.

Hargrove was speaking at a rally held at GM's corporate head office, where angry workers set up a blockade on June 4. They expect GM will seek an injunction to make them move.

Union representatives called on the federal government to protect Canadian jobs by adopting measures which other countries already use. Hargrove said he wanted a rule requiring automakers to build the cars they sell in Canada in Canadian plants.

"That's not very radical," he said.

The government has suggested it may use a green auto fund to help GM.

Earlier Sunday, Canadian Labour Congress president Ken Georgetti called on unions to back the autoworkers.

"I think it's time for some raw shows of force. What you're doing here is exactly what we need to do in the rest of this country. It's time to say enough," he said.

With files from the Canadian Press