MONTREAL -- About 3,200 Canadian National Railway conductors, trainpersons and yard workers could go on strike just after midnight tonight in a job action that would affect freight services if a deal isn't reached with the company.

Passenger rail services in the country's three biggest cities would not be affected, the union said.

The Teamsters Canadian Rail Conference, the union representing the employees, gave the required 72-hour strike notice on the weekend.

The union said it hopes to reach an agreement before the deadline to address safety and scheduling issues, but workers are prepared to walk off the job if their expectations aren't met.

"Our problem is not with the people in general, but with CN," union spokesman Christopher Monette told reporters on Monday.

The union represents workers at commuter rail services including Go Transit in Toronto, Exo in Montreal and the West Coast Express in Vancouver, where passengers would remain unaffected.

Exo spokeswoman Catherine Maurice confirmed Monday there would "not be an impact from this potential strike," but added it was monitoring the situation closely.

CN said it continues to negotiate in good faith and has offered binding arbitration to ensure train services aren't disrupted.

Federal Labour Minister Patty Hajdu said the Federal mediation and conciliation service has been working with the two sides since June and the government is monitoring the situation.

"I am encouraged to see that both parties are still negotiating," Hajdu said in a statement.

The workers, who have been without a contract since July 23, say they're concerned about long hours, fatigue and what they consider dangerous working conditions. They are also fighting against a lifetime cap on prescription drug coverage.

The dispute comes as CN confirmed Friday that it was cutting jobs across the railway as it deals with a weakening North American economy that has eroded demand.

This report by The Canadian Press was first published Nov. 18, 2019.