The federal government introduced back-to-work legislation Friday to end a strike by CN Rail conductors and yard workers.

The strike by 2,800 CN employees began on Feb. 10. Management workers have been filling in for the strikers, but the strike has prompted an outcry from businesses who say their flow of goods is being disrupted.

A worker walks to a switch in a rail yard in Dartmouth, N.S., on Feb. 21, 2007. (Andrew Vaughan/Canadian Press)

Faced with growing calls from businesses for Ottawa to intervene in the strike, federal Labour Minister Jean-Pierre Blackburn introduced legislation Friday in the House of Commons that would force the strikers back to work.

"Currently … the economy is paralyzed in a number of places," Blackburn told the House of Commons, adding that about 15 ships can't load or unload cargo at the Port of Vancouver because of the rail strike.

Blackburn said it could take four to five days to pass the back-to-work legislation.

Businesses in the grain, forestry, chemical and automotive sectors have all said they've been affected by the strike.

Ford Canada closed its St. Thomas, Ont., assembly plant because of a material shortage due to the CN strike, spokeswoman Lauren More told CBC News on Friday.

It's the first closing this week, although several shifts were lost last week.

The company is deciding day-by-day whether the plant can operate, More said.

About 2,300 workers at the plant work two shifts a day making Crown Victoria and Grand Marquis models. The plant doesn't run weekends, so the next decision will be made Monday.

More CN workers return

Before the minister introduced his legislation, Manitoba pickets in Winnipeg, Brandon and Dauphin came down Friday morning.

Lee Rawsthorne of the United Transportation Union local in Winnipeg said the returnees include about 150 workers in Winnipeg, roughly 30 in Dauphin and about six in Brandon.

Workers in Melville, Sask., are also reported to have laid down their picket signs.

Rawsthorne said the national union may not approve of the return to the job, but he said workers felt it was the right thing to do.

"It was never our intention to damage our country," he told CBC News. "It was to try to negotiate a deal.

"Our negotiations are going nowhere right now, and there is no point in holding our country ransom for negotiations."

A CN spokesperson said Friday that roughly 500 workers in the company's eastern region — from Armstrong, Ont., to Halifax — have returned to work.

In other areas, striking workers remained on the picket line.

"Most of our members that I know of, we are holding the line," said Mike Melymick of the UTU's Edmonton local.

"We are still on strike, and we will be until there is a collective agreement in place or we are legislated back," he said.