Business groups are urging Justin Trudeau’s government to put an end to labor strife at Canada’s largest ports, as it did with railways in August, to avoid chaos in the country’s supply chains. Hundreds of dock foremen at British Columbia ports have been locked out for a week. Montreal port employers did the same on November 10, locking out 1,200 unionized employees after those workers rejected a contract offer that included pay increases of about 20% over six years.

Together, the work disruptions are affecting ports that handle some C$1.2 billion ($860 million) of goods a day, businesses say. They want Labor Minister Steven MacKinnon to force the matter to the Canada Industrial Relations Board, which can order the sides to arbitration to resolve the dispute.

That’s the tool he deployed to end work stoppages at Canada’s two largest railways more than two months ago. But the government’s use of it has aroused discontent among some unions. The Teamsters Canada Rail Conference is mounting a court challenge, saying the government’s actions in the railway dispute set a dangerous precedent by violating workers’ constitutional rights.

Soon afterward, the pro-union New Democratic Party tore up a parliamentary pact in which it had agreed to vote with Trudeau’s Liberals to pass key legislation. It’s not clear whether the government could get enough support now to pass a back-to-work bill, if it needed to do so to end the port dispute.

MacKinnon’s office declined to comment.

Michel Murray, a spokesperson for the Montreal Longshoremen’s Union, said in a statement that the port employers “act as bullies,” and if they refuse to negotiate, it means “they clearly want the federal government to intervene.”

“Nearly C$6 billion worth of goods are expected to arrive at the port over the next two weeks,” Michel Leblanc, chief executive officer of the Chamber of Commerce of Metropolitan Montreal, said in a statement. “The urgency is real.”

Goldy Hyder, CEO of the Business Council of Canada, said the disputes “continue to weaken Canada’s economy and tarnish its reputation as a reliable trading partner.”

“Canada’s ports will continue to lose market share if the country’s reputation for labor instability isn’t corrected soon,” Hyder said in a November 9 letter addressed to MacKinnon and Transport Minister Anita Anand. The Montreal offer would have boosted average dockworker compensation to more than C$200,000 per year, according to a group of port employers.