Canada's largest potash mine will temporarily shut down and lay off 550 employees as a result of a strike at Canadian National Railway Co.

Fertilizer giant Nutrien Ltd. notified workers Monday that its mine in southeastern Saskatchewan will halt operations for two weeks starting Dec. 2. The vast majority of the Rocanville mine's product is shipped by CN Rail, which is now operating at 10 per cent capacity.

The announcement comes two days after news broke of 70 short-term layoffs at CN's auto terminal in the Halifax area due to halted car shipments.

Trains have stopped moving across the country as more than 3,000 CN staff hit the picket lines in a nearly week-long strike that has stalled commodities and frustrated farmers who rely on propane to dry their grain and heat their barns and greenhouses.

"It is extremely disappointing that in a year when the agricultural sector has been severely impacted by poor weather and trade disputes, the CN strike will add further hardship to the Canadian agriculture industry," Nutrien chief executive Chuck Magro said in a release.

Last week more than 250 staff at CN's Autoport terminal received layoff notices, but the company later rescinded the notices for 180 employees, according to Unifor.

The sense of urgency around the strike's ripple effects continues to grow. Hundreds of Quebec farmers marched through Montreal streets Monday alongside a convoy of tractors to dump heaps of corn at the steps of Prime Minister Justin Trudeau's riding office, calling on Ottawa to resolve the week-long labour stoppage.

Pascal Leduc, a corn producer from north of Montreal, said that half his crop lies in the fields, which a full silo prevents him from harvesting as winter snows threaten to blanket it, rendering the yield unusable.

"I don't have any propane, and I have grain in my silo which I can't dry," Leduc told The Canadian Press. "I don't want to lose it."

Federal Agriculture Minister Marie-Claude Bibeau urged CN and its workers Monday to reach a deal to alleviate the impact on farmers, saying negotiation "would be the best way for every party and the fastest solution."

"That's not enough," said Garth Whyte, head of Fertilizer Canada, in a phone interview.

"Last we week we were worrying about what could happen. Today it is happening. They can't stretch this out further. Prime Minister Trudeau needs to tell Canadians his plan to end the CN strike. Hoping for a settlement isn't good enough anymore."

Whyte called for binding arbitration -- which CN says it has volunteered to enter -- or reconvening Parliament ahead of the scheduled Dec. 5 date in order to pass back-to-work legislation.

About 3,200 CN conductors, trainpersons and yard workers across the country, who have been without a contract since July 23, walked off the job early last Tuesday morning over worries about long hours, fatigue and what they consider dangerous working conditions.

The strike could cost the Canadian economy upwards of $3 billion if it continues until Dec. 5 -- when Parliament is scheduled to resume -- according to TD senior economist Brian DePratto.

A Nutrien spokesman says about 50 more employees at the mine will likely be affected, but remain on the job.

This report by The Canadian Press was first published Nov. 25, 2019.