The union representing thousands of workers at Canadian Pacific Kansas City Ltd. announced that it has submitted a 72-hour strike notice to the railway.

Teamsters Canada Rail Conference issued a press release stating that unless the two parties reach a last-minute agreement, workers will be off the job starting at 12:01 AM Eastern Time on Thursday.

Shortly after the union's statement, CN Rail issued a notice that it intends to lock out workers at the same time unless an agreement or binding arbitration is reached.

The company said that no tangible progress has been made despite labor negotiations over the weekend.

Both CPKC and Canadian National Railway have halted shipments in preparation for a potential work stoppage by 9,300 railway workers.

Federal Labor Minister Steven MacKinnon on Thursday rejected a request from CN to impose binding arbitration, stating he wants the company to negotiate in good faith.

A spokesperson for CPKC referred the Canadian Press to previous statements. On Friday, the company stated that it is committed to negotiating in good faith and emphasized its existing offer to resolve the matter through binding arbitration.

CPKC previously gave a closure notice to the union at 12:01 AM on Thursday.

The union stated that it is compelled to issue a strike notice to the company to protect the workers.

On Sunday, about 10 hours before the union issued its statement about the strike notice, MacKinnon posted on X that the railway companies are continuing to negotiate with the union alongside federal mediators.