Trudeau says abandoning electoral reform is his biggest regret. Here's how it happened

While taking questions after announcing he would be stepping down as prime minister on Monday, Justin Trudeau was asked to give an example of a regret he had from his time in office.

The prime minister conceded that he could probably think of "many regrets," but he listed one in particular — not moving forward on electoral reform.

"If I have one regret, particularly as we approach this election … I do wish that we'd been able to change the way we elect our governments in this country so that people could choose a second choice or a third choice on the same ballot," he said.

"Parties would spend more time trying to be people's second or third choices and people would be looking for things they have in common rather than trying to polarize and divide Canadians against each other."

During his first federal election campaign as Liberal leader, Trudeau promised that 2015 would be the last time Canadians elect their federal government under the first-past-the-post system — where a candidate wins by simply having the most votes. 

But during that campaign, Trudeau never pushed for a ranked ballot, which allows voters to list their preferred candidates in numerical order. If one person doesn't get a clear majority on the first count, candidates are eliminated and second-choice votes are counted until someone has more than 50 per cent support.

Trudeau and the Liberals would go on to win a majority in the House of Commons — but the prime minister would soon backtrack on his promise to implement electoral reform after momentum steered away from a ranked ballot option.

In their 2015 platform, the Liberals said they would strike an all-party parliamentary committee to review a number of systems — including ranked ballot and proportional representation — and deliver recommendations on the way forward.

A committee was convened and released its report in December 2016. It recommended that a referendum be held that proposed a switch to some form of proportional representation, where the number of seats in the House more accurately reflected a party's share of the popular vote.

The committee report had the sign-off from representatives of the Conservatives and Bloc Québécois — and the NDP and Greens offered an alternative report suggesting that a referendum may not be necessary.

Liberal MPs on the committee released their own supplementary report that disagreed with the rest of the parties entirely.

"The recommendations posed in the majority report regarding alternative electoral systems are rushed and are too radical to impose at this time as Canadians must be more engaged," the Liberals wrote.

Those MPs seemed to have forgotten that it was the Liberal party that proposed a specific timeline for electoral reform by both promising to make 2015 the last election under the current system and by promising to bring in legislation to change the way Canadians vote within 18 months of forming government.