The union representing Canada Post employees is urging the carrier to return to the bargaining table sooner rather than later.
The Canadian Union of Postal Workers (CUPW) rejected a proposal by Canada Post to put on an 80-day "cooling-off" period, which would have been followed by binding arbitration to end the dispute.
CUPW National President Mike Palacek said that plan is just not acceptable.
"We will not accept binding arbitration to resolve our issues with Canada Post. We have the right to collective bargaining and to settle this through negotiations," said Palecek. "We are confident that an agreement can be reached, if only Canada Post would address the issues and stop looking for ways not to negotiate."
The union had until 5 p.m. Monday to accept the proposal, which Canada Post was hoping for so that their mail carriers could focus on the busy holiday season.
The crown corporation had proposed the two parties work together through to January 31. If the CUPW agreed, the rotating strikes would end, Canada Post would not lock out mail carriers, and the corporation would clear away the massive backlog delaying deliveries
On Saturday, the union rejected the corporation's latest offer. It is calling for the federal government to appoint a mediator. Canada Post also agrees that negotiation must resume one way or another.
"With the rotating strikes, resulting backlogs, and the massive Black Friday and Cyber Monday volumes that will arrive within days, we are trying everything we can to work together with the union -- urgently -- to deliver the holidays to Canadians," said Canada Post Interim President and CEO Jessica McDonald.
Rotating strikes are into their fourth week, and almost every mail facility across the country has been impacted.
-With files from Adelle Loiselle