A pre-election rally for Conservative leader Andrew Scheer turned a little too Trumpian for the candidate's own taste on Saturday night when, while speaking about Justin Trudeau, his supporters started chanting "Lock him up! Lock him up!"

The outburst was prompted by Scheer's promise to call a judicial inquiry into the SNC-Lavalin affair, noting that Trudeau had been found "guilty" of breaking ethics laws twice during his term as Prime Minister.

Scheer told an estimated 2,000 people in Richmond Hill that, despite serious accusations of attempted political interference, Trudeau would not let the RCMP investigate his role in the SNC-Lavalin corruption scandal.

"That's why, when we form government, I will hold a judicial inquiry into his scandal to get to the bottom of what he's done," said Scheer of the Liberal leader and current PM.

Tonight at a Scheer Rally in Richmond Hill, ON, the crowd started a “Lock Him Up” chant when Scheer referenced his pledge to have an inquiry into the SNC-Lavalin affair. Scheer tries to move the crowd off “Lock him up” and on to “Vote Him Out” #cdnpoli #elxn43

More at @ctvnews pic.twitter.com/0pmncHOfkQ

— Mackenzie Gray (@Gray_Mackenzie) October 20, 2019

The crowd erupted into cheers and then chants of "Lock him up, lock him up, lock him up," as Scheer tried to continue speaking.

"Well... let's...," said Scheer in an attempt to moderate their behaviour. "We're going to get to the bottom of his scandal... We’re going to vote him out!"

Smiling, Scheer himself started chanting "Vote him out! Vote him out!"

His supporters briefly obliged, echoing the Conservative Party leader for a few seconds before letting him continue with his speech.

Scheer tried to quiet the crowd, and gets them to chant instead “VOTE HIM OUT, VOTE HIM OUT”.

— Katie Simpson (@CBCKatie) October 20, 2019

Scheer may have been able to stop the original chant quickly, but the damage had already been done as Twitter exploded with comparisons of Conservative supporters to fans of Donald Trump during the U.S. President's 2016 election campaign.

"Like Trump supporters shouting 'lock her up' in reference to Hilary Clinton, the Conservative crow in a similar fashion, said, 'lock him up' in reference to Trudeau at a rally yesterday," wrote one Canadian voter. "Another example Trump = Scheer strategy."

"Trump-style swamp politics brought here by Andrew Scheer is infecting Canada and it needs to be stopped," wrote another. "They were chanting Lock Him Up last night at a Con rally. WTF!"

Dear Canada 🇨🇦, we love you just as you are. Please don’t become American. Vote today to keep Trudeau. Andrew Scheer is NOT good for Canada. Did you know they chanted “lock him up” at Scheer rallies and booed the press when they dared ask questions? Sound familiar? VOTE!

— Karen is a Deep State Agent (@geokaren) October 21, 2019

When asked about the chant and its unmistakable resemblance to the "lock her up!" refrain lobbed at Hillary Clinton by Trump supporters (and often) during the 2016 U.S. Presidential election, Scheer's camp admitted that it was "inappropriate."

"Mr. Scheer recognized the chant from a small number of attendees was inappropriate and quickly directed the crowd to chant 'vote him out,'" reads a statement from the Conservative leader's press secretary.

Scheer reaffirmed this position during a press conference on Sunday, telling reporters that "a few individuals" had started a chant which was "quickly turned into a 'vote him out' chant... which is the options Canadians have tomorrow."

Scheer blames last night's "Lock him up" chant on a few individuals, say he has run a positive campaign. #elxn43 pic.twitter.com/cm3dv3PBRY

— Glen McGregor (@glen_mcgregor) October 20, 2019

Canada's 43rd general election takes place today, October 21, 2019. Learn more about where, when and how to vote on Elections Canada's website.