Shippers and producers are holding their breath ahead of a possible strike by thousands of rail workers this month that would halt freight traffic, clog ports and disrupt industries.

A decision by the country’s labour tribunal on whether a strike would jeopardize Canadians’ health and safety is expected by Friday.

The Canada Industrial Relations Board is examining whether any critical shipments must continue in the event of job action, with any would-be work stoppage on pause until a ruling is made.

Observers say the possibility of a strike will likely remain on the table after the decision, as players in industries ranging from agriculture to big-box retail worry about the fallout.

John Corey, president of the Freight Management Association of Canada, whose members include Canadian Tire and Home Depot, says a work stoppage would virtually shut down commodities traffic, with some shippers already rerouting ahead of the potential disruption.

Federal Labour Minister Steven MacKinnon is meeting this morning with leaders from Canada’s two major railways and the union representing some 9,300 workers to discuss the consequences for the economy and supply chain.