Canada’s freight traffic on its two largest railways has simultaneously ground to a halt, threatening to upend supply chains trying to move forward from pandemic-related disruptions.

Canadian National Railway (CN) and Canadian Pacific Kansas City (CPKC) have formally locked out employees represented by the Teamsters Canada Rail Conference (TCRC) on Thursday after failed labor talks, resulting in a shutdown of their rail networks in the country.

The stoppage comes after many talks between the involved parties.

The country’s largest railroad operators issued few days ago lockout notices to the Teamsters Canada Rail Conference (TCRC), a union representing many railway workers.

The parties struggled to reach an agreement on key terms, with both sides accusing the other of bad faith.

“Without an agreement or binding arbitration, CN had no choice but to finalize a safe and orderly shutdown and proceed with a lockout,” CN said in its statement.

CN says it has offered the TCRC a modernized agreement on safety, wages, and work/life balance but this offer was refused.

It also said that the offer was improved in April, but it was also refused by the TCRC. In May it simplified the offer, CN says, and in the absence of any agreement it offered to voluntarily submit to binding arbitration in June.

Each side has accused the other of failing to negotiate seriously. CPKC said it has bargained in good faith for nearly a year of negotiations.

Now the Canadian Pacific Kansas City (CPKC) reiterates that the responsible path for the union is for TCRC and CPKC to engage in binding arbitration to resolve all outstanding disputes.

“CPKC is acting to protect Canada’s supply chains, and all stakeholders, from further uncertainty and the more widespread disruption that would be created should this dispute drag out further resulting in a potential work stoppage occurring during the fall peak shipping period,” CPKC noted yesterday.