McDonald's claims it was justified in walking out of negotiations to end zero-hour contracts because Unite Union changed its demands.
Zero-hour contracts, where workers have to be available for work but have no hours guaranteed, have become common in the fast-food industry.
Burger King and Restaurant Brands, which owns KFC, Pizza Hut, Carl's Jr and Starbucks, have both agreed to end zero-hour contracts.
McDonald's spokesperson Kim Bartlett said it, too, had agreed to end the contracts but needed to come up with a formula to base contracts on.
Two weeks ago, it had said it would look at an employee's "scheduled" hours during the previous 12 weeks and offer them a minimum of 80 percent of that time up to a 32-hour cap; if someone worked an average of 20 hours a week during the 12-week period, they would be offered a guaranteed 16 hours a week contract - and could also be offered extra hours on top.
Unite had taken issue with "scheduled" hours, instead wanting to use "worked" hours - something McDonald's agreed to yesterday.
However, Unite had now changed its position and made further demands, Ms Bartlett said.
"We then left the bargaining table as we did not feel continuing would bring us closer to agreement," she said.
McDonald's believed the union did not want to settle negotiations ahead of its planned strike on Friday - International Workers' Day, Ms Bartlett said.
"Unite have had action planned well in advance, so we believe that whatever had happened yesterday, that they would be going ahead with this action on Friday," she said.
"So we actually really do question their commitment to the bargaining process because of this."
McDonald's remained committed to reaching an agreement, she said.
Unite national director Mike Treen said the union welcomed the company's offer on scrapping the contracts but that the company had "thrown a hissy fit" when the union asked for more information around regular shift patterns.
He acknowledged McDonald's had moved on the formula for establishing hours - "and we were pleased about that" - but said workers also needed a regular shift regime whereby they worked certain days and hours each week.
"And that's your shift, you work that each week and you can plan your life around working that each week," he said.
"That's what negotiations are about."
Mr Treen rejected Ms Barlett's assertion the union wanted the talks to break down so Friday's action could go ahead, saying the union believed an agreement could have been reached yesterday had McDonald's not walked out.
"And we could have continued negotiating today, if need be, before 1 May.
"There's room for compromise on our part around secure shifts, there's room for compromise from them on some other claims that we had as well.
"I think an agreement was possible. They terminated that possibility, not us."