Conservative leadership candidate Kellie Leitch was a last-minute no-show at a debate Sunday south of Ottawa after reports of "threatening activity" and a security alarm sounding at her home earlier on the weekend.

Her campaign manager has suggested the incident could be politically motivated.

Leitch took part in a luncheon portion of the event hosted by the local riding association in Greely, Ont. But she left before the other candidates took to the stage for the afternoon's debate, which was carried live by several media organizations.

At the time, the assembled crowd wasn't told why, but MP Pierre Poilievre, an organizer of the event, told CBC News late Sunday that Leitch had given advance notice she would not be able to stay.

"Dr. Leitch did indeed indicate the night before that she could not attend the debate, but would attend the lunch. She kept her word," Poilievre said.

Organizers had set up 10 chairs on the stage and a table for her campaign.

Initially, a spokesman for Leitch said she needed to be back in Toronto due to "an incident" at her home and had to leave the event.

Break-in attempt?

Later Sunday night, her campaign issued a statement detailing what OPP believe may have been a break-in attempt.

"I have received a number of threats during the course of my time in public life. They are, nevertheless, disquieting," Leitch's statement said, without specifying the nature of the threats.

"This weekend, I was notified by a volunteer in our local riding association that someone was purporting to know my address and was offering it up online to anyone who was interested in doing me harm."

Leitch said this threat was reported to the OPP on Friday evening. Later that night, her home alarm sounded and she left her house and called police, who speculated that someone had tried to gain entry through her garage but then left.

"My campaign team is taking further steps at my expense to enhance security at my home and on the campaign," she said.

Conservative leadership candidate Kellie Leitch participated in the lunch portion of Sunday's event but then left, without explaining to those in attendance or the other leadership candidates why she was not participating in the debate. (Liam Richards/Canadian Press)

An OPP spokesman said officers responded to an incident on Saturday morning at a residence belonging to an unnamed politician, but found no break-in.

"The Huronia West OPP did at approximately 1:55 am on Nov. 12, 2016, respond to a reported break and enter at a residence in the Creemore area belonging to a local politician," said Sgt. Peter Leon.

"Upon arrival, Huronia West OPP members investigated this incident and found that no break and enter occurred although the residential alarm did sound."

'Regrettable' views

Apparently in reference to the distribution of Leitch's personal information, Nick Kouvalis, Leitch's campaign manager, told the National Post, "This is how the left operates and we know that."

Asked by CBC News what he meant by the "how the left operates," Kouvalis said he stood by his remarks.

Organizers suggested up to 500 tickets were sold for the lunch and debate portions of Sunday's Conservative leadership event. The relatively small conference centre was packed. (Fred Chartrand/Canadian Press)

Leitch is believed to be one of the front-runners in the race to succeed Stephen Harper both in terms of her fundraising and support among party members. But she's courted controversy so far, making headlines for her proposal to screen newcomers to Canada for "anti-Canadian values."

Leitch has also continued a strategy that began under Harper of trying to pitch to "everyday Canadians" while railing against the elite. She's compared her populist approach to that of Republican President-elect Donald Trump's last Tuesday, although she says she didn't endorse him nor does she approve of everything he's done.

Fellow candidate Chris Alexander, the former immigration minister who was at Leitch's side in last year's election when Conservatives proposed a barbaric cultural practices tip line, told reporters Sunday that he thought some of the things Leitch has been saying so far in the race were "regrettable" and she was expressing views he doesn't share.

"I don't want to see Canadian politics go in that direction," he said.

'Open mic' event oversold

The Carleton Conservative Association said Sunday's event — billed as the only chance local party members will have to hear from all the contenders in one place — sold out. The room in the small conference facility was packed, with as many as 500 tickets sold, one party official estimated.

The debate, moderated by Poilievre, was open to any member of the public who bought a ticket.

The lunch — dubbed "speed dating" by candidate Erin O'Toole — saw the ten candidates in attendance move from table to table meeting potential supporters as food was served.

None of the 11 questions for the debate were set in advance, organizers said, although one was picked "at random" from Poilievre's Facebook page about ending corporate welfare.

A raffle chose members of the audience to ask their own questions.

As a result, the topics covered Sunday were significantly different from those the party set for the race's first debate in Saskatoon.

Audience members asked about firearms regulations, defence spending, nuclear energy and the age of consent.

Partisans also wanted to hear from potential leaders about what communications strategy they'd use, what their approach would be to federal-provincial relations and how Conservatives could better connect with millennials.

But despite Leitch's suggestion that party members she's talked to want to talk about Canadian values during this race, no questions from the floor Sunday brought this issue up in her absence.

Chong booed over carbon tax proposal

The sharpest divisions in the room arose when candidate Michael Chong's proposal for a revenue-neutral carbon tax was raised. He was booed at one point, prompting Poilievre to ask the crowd to show all participants respect.

At other times, the audience had shown support for Chong, who appeared to have a significant number of supporters in the room, including his wife, children and volunteers who drove up from Toronto.

But his policy runs counter to the position taken by the party under former leader Stephen Harper. Interim leader Rona Ambrose is also leading a strong fight against the now-Liberal government's plans to introduce a price on carbon — something it's clear most of the leadership candidates support, arguing a different approach is required to reduce greenhouse gas emissions.

Candidate Brad Trost took it a step further, expressing again Sunday his view that climate change isn't a real threat.

Chong maintains that Conservatives need a credible approach to reducing emissions, like the one he's advocating based on free market principles.

"People are passionate on both sides of various issues," he said. "That's what we need in this leadership race: a frank, strong debate on the ideas to take this country forward."

"As Conservatives we need to fight for the things we believe in, and that's exactly what I intend to do in this leadership race," he said to reporters after the event.

All 12 candidates for the Conservative Party leadership were in Saskatoon on Wednesday for the first of five party-organized debates. On Sunday, 10 of the candidates were at the riding association event in Greely south of downtown Ottawa. (Liam Richards/Canadian Press)

The nine candidates who participated in the debate were: Chris Alexander, Maxime Bernier, Michael Chong, ​Deepak Obhrai, ​Erin O'Toole, Lisa Raitt, Andrew Saxton, Andrew Scheer and Brad Trost.

Steven Blaney and Dan Lindsay did not attend.

There is already a large field — with two or three others possibly joining the 12 before the February deadline.

The ranked-ballot format the party's using means candidates must maximize both their first-choice endorsements and their ability to grow support among possible second- or third-choice supporters.

Four more party-organized debates are planned, including a bilingual one in Moncton, N.B., on Dec. 6.

Over the next six months of campaigning, more riding associations or Conservative groups can organize forums like Sunday's event in Greely.

If a candidate skips one of the party-organized debates, he or she will be fined $10,000. There was no penalty for Leitch's departure Sunday.