Employers at ports in British Columbia will lock out unionized supervisors, a move that threatens to freeze trade on Canada’s West Coast and add to the country’s supply chain disruptions.

Workers at two West Coast ports, including the Port of Vancouver, the largest facility in Canada, are now locked out. The lockout went into effect at 4:30 p.m. Monday. The British Columbia Maritime Employers Association (BCMEA),

The BC Maritime Employers Association said it would lock out workers on Monday at Canada's Port of Vancouver after a negotiating deadline passed, potentially disrupting exports of coal, potash and beef.