The union at Canada Post says its rotating strikes have begun in four cities across the country after the Monday morning deadline passed without a deal being reached.
The Canadian Union of Postal Workers says strikes started at 12:01 a.m. Monday in Victoria, Edmonton, Windsor and at 1:01 a.m. in Halifax and will last for 24 hours.
CUPW President Mike Palecek says Canada Post has refused to talk about issues that matter to the union, which include job security, an end to forced overtime, better health and safety measures and gender equality.
The union says mail will still be delivered in those cities, but will be delayed.
Canada Post says it has an offer on the table that includes wage increases, job security, improved benefits and no concessions.
Spokesman Jon Hamilton says mail will be delivered in all other locations across the country in the event of a strike.
He says they remain committed to negotiating a deal.