Senators on Monday evening voted in favour of the Liberal government's back-to-work legislation for Canada Post employees.
The Senate vote, which passed by a margin of 53 to 25 with four abstentions, put an end to six weeks of rotating strikes.
The bill could receive royal assent and become law a short time later, which would force striking postal workers back to work by noon on Tuesday.
Even though Canada Post workers have been legislated back to work, the Canadian Union of Postal Workers has told its members that it will soon begin a campaign of "mobilizations, demonstrations and non-violent civil disobedience".
Along with its request for safety improvements in the workplace, the CUPW wants better pay, job security, guaranteed hours and equality.
Combined with the costs associated with the rotating walkouts that began October 22 and came to a forced end on Tuesday, Canada Post said it expected to end 2018 with a loss, and that pay equity would result in ongoing annual costs of about $140 million.
Canada Post has said millions of parcels and other pieces of mail are backlogged and delayed due to the rotating strikes.
Earlier Monday, picket lines were up in parts of the province of British Columbia, including Vancouver, Richmond and Surrey, and in parts of Ontario, including Hamilton, Ajax, North York, Pickering and London.
Canada Post workers in Orillia say it's a slap in the face.
Despite the likely passing of the bill, Canada Post said on Monday backlogs that of both mail and parcels in our network are severe, and customers should continue to expect delays for the foreseeable future.
The union says the Halifax-area workers will not process or deliver mail until further notice.
It will ultimately be up to the courts to decide whether the legislation is constitutional, Labour Minister Patty Hajdu said on her way into a morning meeting with her cabinet colleagues, should it be legally challenged by CUPW.
We won the battle against the back-to-work legislation.
"After 37 days of rotating strikes, unconstitutional legislation has removed the right to strike for postal workers", said CUPW national president Mike Palecek. "And it still might be too late", Conservative Sen.
The legislation was a last resort after the government spent over a year trying to see Canada Post and the Canadian Union of Postal Workers (CUPW) reach a new collective bargaining agreement.
But another independent, Sen.
"Because the right to strike is a fundamental right. I am convinced that more time should be allowed for negotiations to come to a fruitful conclusions", he said.