The Facebook event — Trudeau Promised Electoral Reform — was set for April 20, exactly 18 months after the election. Urquhart said it grew from a reminder for herself and five friends to something thousands of people were interested in.
"It went viral really quickly and obviously tapped into something," she said.
Organizers had demonstrations in the works for cities across the country, Urquhart said. The date is likely to get moved up now, and the event could bring thousands of people out to protest the government's decision.
"The running theme of our group has been a cautious optimism," Urquhart said. "Because the promises were so concrete, it was such a central part of the campaign, that people wanted to give the Liberals and the prime minister the benefit of the doubt."