Canada Post is accusing the union representing its more than 55,000 workers of showing "little meaningful movement" during mediated negotiations over the weekend to end a labour dispute that saw employees ordered back to work late last year.
A statement from Canada Post on Sunday says the Crown corporation put forward "a workable and affordable weekend delivery model" it says would make it competitive for parcel delivery, using a dedicated part-time workforce.
But it says the Canadian Union of Postal Workers "failed to acknowledge the significant challenges" facing Canada Post and says it is disappointed no deal could be reached on the weekend.
The union says in its own statement on Sunday that Canada Post "continued to push for serious rollbacks" that it claimed would gut its agreements, "explode part-time and temporary work," and threaten full-time jobs.
Both sides began mediated talks after a countrywide strike, which ended in December when the government directed the labour board to order the employees back to work if a deal couldn't be reached before the end of the year.
The two parties are also in the midst of hearings as part of a federal inquiry looking at the structural and business issues facing Canada Post, and the union says it will continue with its constitutional challenge before the Canada Industrial Relations Board of December's back-to-work order.