LONDON, Ont. -- Erin O'Toole delivered one of his last pitches to Canadians ahead of Monday's vote while standing under the glaring Ontario sun -- but a noted rise in support for the People's Party of Canada may also have the Conservative leader feeling the heat.

O'Toole pushed his sharpest message yet to those angry about Justin Trudeau's Liberal government who are considering casting a ballot for what he referred to as "smaller parties."

Although he declined to name which of the main political parties he was talking about, he didn't need to.

Political watchers, including Conservatives, have increased their warnings in recent days about splitting the vote on the right with Maxime Bernier's populist PPC, which could sink the Tories' chances of defeating the Liberals in a race that has been razor tight.

A Leger poll released earlier this week in collaboration with The Canadian Press indicated the Liberals and Conservatives are tied with the support of 32 per cent of decided voters and that the People's Party was at five per cent support.

O'Toole noted the anger people feel toward the Liberal leader, which has been illustrated by the crowds of protesters who have followed him across the country during the campaign, swearing and chanting to "lock him up," channelling their staunch opposition to vaccine mandates and other health measures to prevent the spread of COVID-19, which Trudeau forcefully supports.

Some of those in the crowds have been PPC supporters, seen holding the party's signs. The party booted one of their Ontario riding association president's after allegations surfaced he threw gravel at Trudeau while he was there on a campaign stop.

The Conservative leader said Friday that Trudeau has addressed these protesters, "but there's actually millions of Canadians who are very frustrated with Mr. Trudeau."

"And if they allow that frustration to do anything other than vote Conservative, they're voting for Mr. Trudeau," O'Toole said at a campaign stop in London, Ont., where Bernier recently held a rally.

"There are five parties, there are two choices: More of the same with Mr. Trudeau, or real change and ethical government with a plan, with Canada's Conservatives."

Among the candidates who echoed O'Toole's sentiment was Leslyn Lewis, a former leadership rival of his who was heavily backed by social conservatives and is now running for election in Ontario, where the Tories need to gain seats if they hope to form government.

"A vote for the PPC is a vote for Trudeau," she tweeted Friday. "Let's stand united (and) get the job done for the sake of our country and our future."

Dan Robertson, chief of strategy for O'Toole, also tweeted Friday: "The stakes are too high."

"There's no such thing as a wasted vote. Every vote sends a message. If that's your goal, fine. But if your goal is to show Justin Trudeau the door, only the Conservatives can do that."

This is the second election for Bernier as leader of the PPC. The former Tory MP from Quebec lost his seat in the 2019 vote, and didn't come close to electing a single MP in the race, where he campaigned on immigration reform and attacking the Conservatives for faking their political values.

This time around he's trying to galvanize support by coming out hard against mandatory vaccinations and provinces using a passport-like system for vaccines to allow people to access businesses and events.

O'Toole has also said he's against making it an all-or-nothing rule that someone must get vaccinated, and instead favours allowing those who are not immunized, regardless of the reason, to undergo regular rapid testing, because he respects an individual's right to make their own choices about their health.

Despite that, candidates have found themselves having to explain that to voters questioning them at the doors.

"If we want to say goodbye to Justin Trudeau, Conservatives have to stay united and we can do just that on Sept. 20," said Manitoba incumbent MP Candice Bergen, who is the party's deputy leader, in a video posted to Instagram Thursday.

Bergen confirmed she is double vaccinated against COVID-19 and that while Conservatives believe these shots are safe and effective, they respect those who are unvaccinated and accused Trudeau of using the issue to divide Canadians.

O'Toole has spent most of the past 30 days campaigning for votes from people who don't bleed Tory blue, telling them "we're not your dad's Conservative Party anymore." He has also pointed promises he's made to tackle climate change, such as getting more electric vehicles on the road and adopting a Conservative carbon price -- something he said they failed to do in the past.

The leader has championed his own more progressive outlook on a woman's right to choose to have an abortion, and his commitment to protect LGBTQ rights.

Even though he's distanced himself from the leadership of Andrew Scheer and Stephen Harper in public, O'Toole has said he has spoken to Harper since taking over the helm of the Conservatives, but didn't disclose what they discussed.

With three days left to go in the race, O'Toole travelled from Nova Scotia to Ontario on Friday, ditching the campaign plane to spend the next few days travelling around the southwestern Ontario and the Greater Toronto Area, where the party is fishing for seats.

The Conservatives have one goal over the next few days and that is to get out the vote. O'Toole spent Friday afternoon travelling to the campaign offices of London West candidate Rob Flack and Brantford-Brant hopeful Larry Brock.

The leader traded talking policy for dropping off doughnuts and coffee to volunteers at Brock's office, telling a crowd of volunteers and supporters to do all they can to send the candidate to Ottawa.

This report by The Canadian Press was first published Sept. 17, 2021.