The federal Liberals needed a stronger ground campaign in their fortress riding of Toronto—St. Paul, including more time to campaign before the vote, suggested several members of the party.

The Liberals lost their 30-year grip on the riding when the seat flipped to the Conservatives in a byelection on June 24.

Carolyn Bennett, who represented the riding for the Liberals since 1997 until her January resignation, had deep roots in the area.

Leslie Church, a longtime Liberal political aide, lost by about 600 votes to Conservative Don Stewart, a financial executive.

Ms. Bennett signaled last July that she would not be seeking re-election in the riding, and announced a plan to step away early on Dec. 12 when she delivered her final speech in the House of Commons. She officially submitted her resignation in mid-January.

The Conservatives moved quickly to nominate Mr. Stewart, and had him in place in February. While Ms. Church had announced her intention to run even before Ms. Bennett announced her resignation in December, the party did not officially complete the nomination until May 1.

Eighteen days later Prime Minister Justin Trudeau called the byelection.

“I think the lesson here is that she was nominated a week or two before the byelection was called,” said Liberal MP Karina Gould, who represents a riding west of Toronto.

“And so she needed more time to be able to get out there and get known in the riding.”

Mr. Stewart, who has declined an interview with The Canadian Press, was seen on social media throughout the year door-knocking, attending community events, and speaking to residents in the area. He even noted when constituents proclaimed to him that no other candidates had knocked on their door before.

Ms. Church could not officially start her campaign until months after Mr. Stewart.

One resident in the area said she voted for the Liberals, but was so disappointed in the outcome that she decided to write the party “to tell them how they screwed this up.”

The party got “lazy” because of how long it had held the seat, said Andrea who declined to provide her last name. “We are a left-leaning Liberal area and somehow a Conservative got in, so obviously something got messed up,” she said.

Ms. Gould said it’s becoming tougher for Liberal candidates to campaign because people are seeking change from a government that’s been in power for nine years as they also struggle to pay rent and put food on the table.

That means candidates need to have tougher, longer conversations with Canadians, and to make sure they can demonstrate that they’re listening.

“I think (Church) did a great job, she gave it her all, but really what we learned is that there’s a lot of frustration out there,” Ms. Gould said.

“People are feeling like we need to do a better job of listening to them, and demonstrating that we hear what their frustrations are.”

British Columbia Liberal MP Ken Hardie, who is not seeking re-election, has said Ms. Church needed to develop deeper roots in the community.

While Ms. Church had strong connections to Ottawa as former chief of staff to Deputy Prime Minister Chrystia Freeland, Mr. Stewart focused on promoting his connections to the community, of which he had lived in since 2016 with his two daughters.

For Liberal MP Shafqat Ali, who represents Brampton Centre, the loss showed him that his party needed to do a better job getting out the vote.

As is typical during a byelection, overall turnout was just 44 percent, compared with 65 percent in the 2021 general election, with 17,000 fewer votes cast.

Despite that the Conservatives still increased their vote total by almost 2,000 votes, while the Liberals lost more than 11,000 votes.

Mr. Ali said the Liberal vote just stayed home.

“They didn’t go and vote against the Liberals” he said in a recent interview with The Canadian Press.

“I can see we were not able to motivate them. We were not able to communicate with them how important it is to come out and vote,” he said.

“They stayed home and we need to do more to get their trust, and motivate them to vote Liberal, and communicate how important it is to make their vote count.”

Voter Ante Pavic, who voted in the by-election, said the cost of living was top of mind for him and he hopes Conservative Leader Pierre Poilievre will win the next election.

Mr. Poilievre, who has led in opinion polls ahead of the Liberals since last summer, has heavily campaigned on affordability measures, and axing the Liberal’s price on pollution, which he says is making everything more costly for people.

Marty, a lifelong Liberal voter who declined to provide his last name, said he switched his vote to Conservative during the byelection as “an opportunity to send a message” to Prime Minister Justin Trudeau.

The loss sent shockwaves through the Liberals, with several former cabinet ministers openly clamoring for Mr. Trudeau to step down. Within the caucus there is unrest but thus far only New Brunswick MP Wayne Long, who isn’t running again, has publicly called for Mr. Trudeau’s resignation.

The Liberal party will be spending the summer reflecting and analyzing what happened in Toronto—St.Paul, Ms. Gould said, before they’re scheduled to meet in late summer for a national caucus meeting.

“A loss is a loss,” Ms. Gould said.

“I’m not going to pretend that was a good result for us, but it’s also an opportunity for us to say what happened, what went wrong, what can we learn, and how can we make sure we apply those lessons over the next year as we head into the next general election.”

While some MPs have called for a national caucus meeting sooner, Ms. Gould said the focus needs to be talking to Canadians.

“I think what’s important is that caucus members are really engaging their community, really hearing what’s on people’s minds,” she said, “so that when we do get together we can have a really constructive dialogue about what the next year looks like, and what our plans are.”