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.

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.

Dock employers in British Columbia said they will shut out workers on Monday in response to a union’s strike notice, grinding trade to a halt at terminals across Canada’s busiest and third-busiest ports.