"Hey hey! Ho ho! First past the post has got to go," rang out in front of Yukon MP Larry Bagnell's office in downtown Whitehorse Tuesday as about 50 people protested the Liberal government's decision to abandon electoral reform.

The protesters said Prime Minister Justin Trudeau broke their hearts when he broke his promise.

Protester Emma Eaton, sign in hand reading "I want you to keep your promise," said she voted for Bagnell in part because he promised that the 2015 election would be the last time Canadians voted under the current electoral system.

Emma Eaton said she's upset that the federal government took the discussion over electoral reform off the table. She says that issue is the main reason she voted for Larry Bagnell as Yukon MP. ​ (Meagan Deuling/CBC)

"They were very clear in what they planned to do; this wasn't a vague promise, and it's just been discarded," said Eaton.

When she heard that the Liberals were backing out of this promise, she said her "heart just sunk." Now, Eaton said, "I just can't trust them."

Eaton said she wants people to write letters to their members of parliament, to talk to their neighbours, talk to their friends, and think twice before supporting the Liberals in the next election.

"We are here to tell the government it's not acceptable," said Jason LaChappelle, one of the protest's organizers.

When the government said it wasn't going to go forward with electoral reform because there isn't a consensus among Canadians, it was a "betrayal and insult," said LaChappelle.

He said there is a consensus with all the experts and teams who took the time to participate in consultations with the government wanting proportional representation.

Bagnell apologized last week to voters frustrated that the federal Liberals have abandoned their commitment to electoral reform..