The Canadian Union of Postal Workers says it has given strike notice to Canada Post that workers could walk off the job as early as next week.
The union representing 50,000 Canada Post employees said rotating strikes will begin Monday if agreements aren't reached with the Urban Postal Operations and Rural and Suburban Mail Carriers bargaining units.
The scale of the job action will depend in part on how talks go in the coming days, but union president Mike Palecek said they would look to avoid inconveniencing the public.
"Our aim is not to disrupt the public, it's not to disrupt the service that we provide, that we've been defending for years, so we're trying to come up with ways to put some pressure on Canada Post without impacting the public."
The union decided to issue the strike notices after the nearly year-long talks stalled with the two sides fairly far apart, said Palecek.
"We've said we would remain at the table as long as progress is being made, and we've reached a point where we're not seeing a lot of progress."
He said the union, which provided five days notice rather than the 72 hours required, hopes the threat of job action will help the Crown corporation take the issues seriously.
The union has been pushing for 3.5 per cent annual wage increases but has been met with offers of increases below inflation, while health and safety concerns have also yet to be addressed, said Palecek.
Canada Post spokesman Jon Hamilton said in a statement that the service has found common ground with the union on several issues including workload concerns and has made meaningful offers.
"Canada Post has made significant offers to CUPW which include increased wages, job security, and improved benefits and has not asked for any concessions in return."
The postal service will still be operational in the event of a strike, said Hamilton.
"Canada Post will remain open for business, continuing to operate if the union decides to conduct rotating strikes across the country next week. We will notify customers of any disruptions planned by the union as soon as we are aware, however customers may experience some minor delays."
The possibility of a work stoppage has hovered over Canada Post since Sept. 26 after postal workers voted overwhelmingly in late summer in support of a potential walkout to back their contract demands.
Canada Post is the biggest parcel shipping company in the country, having delivered about one million parcels per day during the holiday season last year – an increase of 20 per cent over the same period in 2016.
The postal service also has contracts with numerous provinces to deliver the legal online cannabis sales that begin Wednesday, including Ontario where online sales will be the only source of the product until next April.