Canada’s rail system is facing a systemwide shutdown before the end of the month after the country’s rail workers voted in favor of a strike, their union announced on May 1.

The union, representing more than 9,000 employees at Canadian National Railway and Canadian Pacific Kansas City, announced that 95% of its members approved of a strike.

The dispute centers on wage increases and scheduling changes. The union rejected Canadian National’s offer for wage boosts, scheduled consecutive days off, provisions for no layoffs and reduced hours from home.

Giving the union permission to call a strike is not the final action before a work stoppage. The railroad companies and the union entered a 21-day “cooling down” period with federal mediation, meaning a strike could begin as early as May 22 if an agreement is not reached, disrupting the transport of products including coal, minerals and petroleum beyond the Canadian border.

The companies’ contracts for engineers, conductors and yard workers expired at the end of 2023, and negotiations have been ongoing for six months.